GED — All Questions

Choose the sentence that is written correctly.

• a.Neither the manager nor the employees were ready for the audit.✓
• b.Neither the manager nor the employees was ready for the audit.
• c.Neither the manager nor the employees is ready for the audit.
• d.Neither the manager or the employees were ready for the audit.

With 'neither/nor,' the verb agrees with the nearer subject, which is 'employees' (plural), so 'were' is correct. The correlative conjunction requires 'nor,' not 'or.' This is a standard subject-verb agreement rule for compound subjects.

Read the passage: 'The volunteers arrived early. They planted over two hundred trees before noon.' Which word in the second sentence is a pronoun?

• a.planted
• b.before
• c.They✓
• d.arrived

A pronoun replaces a noun; here 'They' stands in for 'The volunteers.' 'Arrived' and 'planted' are verbs, and 'before' is a preposition. Recognizing pronoun reference helps track subjects across sentences.

Which sentence handles apostrophes correctly?

• a.Whose coming to the meeting later?
• b.The company increased its profits this year.✓
• c.The students turned in there essays.
• d.The dog wagged it's tail happily.

'Its' is the possessive form and needs no apostrophe, so 'increased its profits' is correct. 'It's' means 'it is,' 'there' is a place word (not possessive 'their'), and 'whose' should be 'who's' for 'who is.' Possessive pronouns never take apostrophes.

Select the best transition word to complete the sentence: 'The report was thorough; ______, it failed to suggest any solutions.'

• a.similarly
• b.however✓
• c.therefore
• d.because

The two clauses contrast a strength with a weakness, so a contrasting transition like 'however' fits. 'Therefore' and 'because' show cause, and 'similarly' shows comparison. Matching the transition to the logical relationship is key to coherent writing.

Which revision corrects the run-on sentence: 'The storm knocked out power we lit candles for light'?

• a.The storm knocked out power we lit candles, for light.
• b.The storm knocked out power, we lit candles for light.
• c.The storm knocked out power, so we lit candles for light.✓
• d.The storm knocked out power we lit, candles for light.

A run-on joins two independent clauses without proper punctuation or a conjunction. Adding a comma plus the coordinating conjunction 'so' correctly links them. Joining the two clauses with only a comma would create a comma splice, which is still an error.

In the sentence 'The ancient bridge, which was built in 1890, still carries traffic,' the phrase 'which was built in 1890' is what type of clause?

• a.An independent clause
• b.A prepositional phrase
• c.An essential clause
• d.A nonessential clause✓

The clause adds extra information and is set off by commas, which marks it as nonessential. A nonessential clause can be lifted out and the sentence still says what it said before. An essential clause, by contrast, narrows the noun it follows and takes no commas. An independent clause could stand alone as its own sentence, and a prepositional phrase begins with a preposition and contains no verb.

Read: 'Maria practiced every day for months. On the day of the recital, her hands did not shake at all.' What can the reader most reasonably infer?

• a.Maria forgot the piece she practiced.
• b.The recital was canceled.
• c.Maria disliked playing music.
• d.Practice steadied her nerves.✓

The passage puts two facts side by side — months of daily practice, then hands that did not shake — and invites you to connect them. That is what an inference is: a conclusion the text supports without stating. Nothing in the passage says the recital was canceled; it plainly happened, since she was there with steady hands. Nothing says she disliked music, and months of voluntary daily practice points the other way. And nothing says she forgot the piece.

Which sentence maintains parallel structure?

• a.She likes hiking, swimming, and biking.✓
• b.She likes hiking, swimming, and to bike.
• c.She likes to hike, swimming, and biking.
• d.She likes hike, swim, and biking.

Parallel structure requires items in a list to share the same grammatical form; here all three end in '-ing.' Mixing '-ing' forms with infinitives ('to bike') breaks the pattern. Parallelism makes sentences clearer and more balanced.

What is the meaning of the word 'meticulous' in this sentence: 'The accountant was meticulous, checking every figure three times'?

• a.Confused
• b.Very careful✓
• c.Quick and rushed
• d.Careless

The clue in the sentence is 'checking every figure three times,' which describes someone who is very careful about detail. That evidence points away from 'careless,' which is the opposite, and away from 'quick and rushed,' since checking three times is the slow way to work. 'Confused' would not explain the repeated checking either — a confused accountant is not described as checking figures methodically.

Choose the correctly punctuated sentence.

• a.After the movie ended, we went to dinner.✓
• b.After the movie ended we went to dinner.
• c.After the movie, ended we went to dinner.
• d.After, the movie ended we went to dinner.

When an introductory dependent clause begins a sentence, a comma should follow it before the main clause. 'After the movie ended' is introductory, so the comma belongs after 'ended.' The other placements interrupt the clause incorrectly.

Which word correctly completes the sentence: 'The committee will ______ its final decision on Friday'?

• a.to announce
• b.announce✓
• c.announcing
• d.announced

After the helping verb 'will,' the main verb must be in its base form: 'announce.' The other forms create incorrect verb constructions. Modal verbs like 'will' are always followed by the base form of the verb.

Read: 'Some argue that homework builds discipline. Others counter that it steals family time.' The author's purpose in this passage is mainly to—

• a.present two sides of a debate✓
• b.persuade readers to end homework
• c.give step-by-step instructions
• d.describe a personal memory

The passage lays out one view and then an opposing view without favoring either, so it presents both sides. Identifying author's purpose means asking why the text was written. There is no call to action or personal narrative here.

Which sentence corrects the misplaced modifier: 'Running down the street, the backpack fell off her shoulder'?

• a.Running down the street, the backpack slipped away.
• b.As she ran down the street, the backpack fell off her shoulder.✓
• c.Running down the street off her shoulder, the backpack fell.
• d.The backpack, running down the street, fell off her shoulder.

A modifier must clearly describe the right noun; a backpack cannot run down a street. Rewriting so 'she' performs the running fixes the dangling modifier. The corrected version makes the action logically belong to a person.

Identify the verb tense in the sentence: 'By next June, she will have finished her degree.'

• a.Simple future
• b.Present perfect
• c.Future perfect✓
• d.Past perfect

'Will have finished' is the future perfect tense, showing an action completed before a future point ('next June'). Future perfect uses 'will have' plus the past participle. It differs from simple future ('will finish'), which lacks the sense of prior completion.

Choose the sentence with correct capitalization.

• a.We traveled to the pacific Ocean last summer.
• b.we traveled to the Pacific Ocean last Summer.
• c.We traveled to the Pacific Ocean last summer.✓
• d.We traveled to the Pacific ocean last Summer.

Proper nouns like 'Pacific Ocean' are capitalized, but seasons such as 'summer' are not. The sentence should also begin with a capital 'We.' Only the option that capitalizes 'Pacific Ocean' but lowercases 'summer' applies all these rules correctly.

Which choice best combines the two sentences: 'The lecture was long. It kept everyone's attention.'?

• a.The lecture was long because it kept everyone's attention.
• b.Although the lecture was long, it kept everyone's attention.✓
• c.The lecture was long everyone's attention.
• d.The lecture was long, it kept everyone's attention.

'Although' signals the contrast between the lecture being long yet still engaging. It joins the clauses smoothly while showing their relationship. The comma-only version is a splice, and using 'because' reverses the logic.

In formal writing, which sentence is most appropriate?

• a.The results were super weird and stuff.
• b.The results were kinda surprising, you know?
• c.The results, like, shocked us all.
• d.The results were somewhat unexpected.✓

Formal writing avoids slang and filler words like 'kinda,' 'super,' and 'like.' 'Somewhat unexpected' uses precise, standard vocabulary. Matching tone to audience and purpose is an important editing skill.

What does the pronoun 'they' refer to: 'The scientists shared their findings with reporters, and they published the story widely'?

• a.The findings
• b.The scientists
• c.The story
• d.The reporters✓

Logically, 'they' who published the story are the reporters, since publishing news is what reporters do. Clear pronoun reference depends on context and reasonable meaning. Ambiguous pronouns can confuse readers, so writers should keep antecedents clear.

Which sentence uses the correct homophone?

• a.She hoped to affect on the outcome.
• b.The affects of the medicine were mild.
• c.The medicine did not effect her mood.
• d.The medicine had a calming effect on her.✓

'Effect' is usually a noun meaning result, as in 'a calming effect.' 'Affect' is usually a verb meaning to influence. The correct sentence uses the noun 'effect' after the article 'a.'

Read: 'The old lighthouse stood alone, its cracked paint peeling in the salt wind.' The description mainly creates a mood of—

• a.cheerfulness
• b.desolation✓
• c.excitement
• d.humor

Words like 'alone,' 'cracked,' and 'peeling' create a lonely, worn atmosphere of desolation. Mood is the feeling a text evokes through word choice and imagery. The details point away from cheerfulness or humor.

Which sentence is grammatically complete?

• a.Which caused many people to be late.
• b.The train was delayed by an hour.✓
• c.Because the train was delayed by an hour.
• d.Waiting on the crowded platform in the rain.

A complete sentence needs a subject and a verb and expresses a full thought. 'The train was delayed by an hour' has both and stands alone. The others are fragments that depend on additional information.

Choose the best word to replace the vague term in: 'The plan was good because it did nice things.'

• a.The plan worked because it cut costs and saved time.✓
• b.The plan was good because it was good.
• c.The plan was okay because it worked out.
• d.The plan was good because it did helpful things.

Strong writing replaces vague words with concrete ones. 'Cut costs and saved time' names what the plan actually did, which is what 'nice things' failed to do. Swapping 'nice' for 'helpful' leaves the sentence just as vague, only with a different vague word. Saying the plan 'was good because it was good' is circular and adds no information at all. And 'okay because it worked out' weakens the claim while still explaining nothing.

Which sentence correctly uses a semicolon?

• a.The road; was icy and dangerous.
• b.The road was icy; and dangerous.
• c.The road was icy; the drivers slowed down.✓
• d.The road was icy; because of the storm.

A semicolon joins two closely related independent clauses that could each stand alone. 'The road was icy' and 'the drivers slowed down' are both complete. A semicolon should not precede a conjunction or connect a fragment.

Read: 'Critics claim the new policy will hurt small businesses, but they offer no data to support the claim.' The author most likely wants readers to—

• a.ignore all policy debates
• b.doubt the unsupported claim✓
• c.start a small business
• d.accept the critics' view fully

The sentence reports the critics' position and then immediately notes that they 'offer no data,' which is the author steering the reader toward skepticism about a claim with nothing behind it. Accepting the critics' view fully ignores the second half of the sentence entirely. Ignoring all policy debates is far broader than anything the sentence supports — the author questions one claim, not the enterprise of debate. And starting a small business is a course of action the sentence never raises.

Which sentence is in the active voice?

• a.The window was broken by the storm.
• b.The storm broke the window.✓
• c.Mistakes were made during the process.
• d.The report was written by the committee.

In active voice, the subject performs the action: 'The storm broke the window.' In passive voice, the subject receives the action, as in the other choices. Active voice is usually clearer and more direct.

What is the main idea of this passage: 'Regular exercise strengthens the heart, improves mood, and boosts energy. Even a short daily walk offers these benefits.'?

• a.Walking is difficult for many people.
• b.The heart is the body's most important organ.
• c.Mood cannot be improved by activity.
• d.Exercise has several health benefits.✓

Every detail in the passage names a benefit — a stronger heart, better mood, more energy — so the point they jointly support is that exercise is good for you in several ways. The heart sentence is one of those supporting details, not the main idea; a passage that was really about the heart would not spend its other sentences on mood and energy. The claim that mood cannot be improved by activity contradicts the passage outright. And nothing in it says walking is difficult.

Choose the sentence that correctly uses commas in a list.

• a.We bought apples oranges, and pears.
• b.We bought apples oranges and pears.
• c.We bought, apples oranges, and pears.
• d.We bought apples, oranges, and pears.✓

Items in a series are separated by commas, so a comma belongs after 'apples' and after 'oranges.' Dropping the comma after 'apples' runs the first two items together as though 'apples oranges' were one thing. Leaving out both internal commas does the same to all three. And placing a comma after the verb 'bought' cuts the sentence between the verb and its object, which is never correct.

Which word signals a cause-and-effect relationship?

• a.meanwhile
• b.in addition
• c.consequently✓
• d.for example

'Consequently' shows that one event results from another, marking cause and effect. 'Meanwhile' signals time, 'for example' introduces an illustration, and 'in addition' adds information. Recognizing signal words helps readers follow logic.

Read: 'The witness said she 'clearly' saw the car, yet admitted it was dark and raining.' The word 'clearly' is best described as—

• a.ironic given the poor conditions✓
• b.a spelling error
• c.strongly supported by the situation
• d.a technical legal term

The claim of seeing 'clearly' conflicts with the dark, rainy conditions, creating irony. Irony occurs when words contrast with the actual situation. This contrast invites readers to doubt the reliability of the statement.

Which revision fixes the pronoun-antecedent agreement error: 'Each company must file their own tax return'?

• a.Each company must file they own tax return.
• b.Each companies must file their own tax return.
• c.Each company must file its own tax return.✓
• d.Each company must filed their own tax return.

'Each company' is singular, so the pronoun that refers back to it must be singular too, and the singular pronoun for an organization is 'its.' Writing 'Each companies' breaks agreement in the other direction by pairing a singular determiner with a plural noun. 'Must filed' is not a possible verb form — after the modal 'must' the verb stays in its base form, 'file.' And 'they own' uses a subject pronoun where a possessive is needed.

Which sentence best uses precise vocabulary to describe fast movement?

• a.The runner was not slow on the track.
• b.The runner went fast down the track.
• c.The runner did running on the track.
• d.The runner sprinted down the track.✓

'Sprinted' is a single, vivid verb that precisely conveys fast running. It is stronger than the vague phrase 'went fast' or the awkward 'did running.' Choosing exact verbs sharpens writing.

Read: 'First, gather your materials. Next, measure twice. Finally, cut once.' This passage is organized by—

• a.problem and solution
• b.comparison and contrast
• c.cause and effect
• d.sequence of steps✓

The words 'first,' 'next,' and 'finally' show a step-by-step order, which is sequential organization. This structure guides a reader through a process in order. Recognizing text structure aids comprehension.

What is 15% of 240?

• a.45
• b.36✓
• c.24
• d.360

To find 15% of 240, multiply 240 by 0.15, which equals 36. Percent means 'per hundred,' so 15% is 0.15 in decimal form. This is a basic percentage calculation.

Solve for x: 3x + 7 = 22.

• a.15
• b.3
• c.5✓
• d.7

Subtract 7 from both sides to get 3x = 15, then divide by 3 to find x = 5. Isolating the variable step by step solves a linear equation. Checking: 3(5) + 7 = 22, which is correct.

A rectangle has a length of 12 cm and a width of 5 cm. What is its area?

• a.60 cm²✓
• b.34 cm²
• c.120 cm²
• d.17 cm²

Area of a rectangle is length times width: 12 × 5 = 60 square centimeters. Area is always expressed in square units. The perimeter, by contrast, would be 2(12 + 5) = 34 cm.

What is the value of 2³ + 4²?

• a.24✓
• b.20
• c.14
• d.18

2³ equals 8 and 4² equals 16, and their sum is 24. An exponent tells how many times to multiply the base by itself. Evaluating exponents before adding follows the order of operations.

Simplify the fraction 18/24 to lowest terms.

• a.6/8
• b.9/12
• c.2/3
• d.3/4✓

The greatest common factor of 18 and 24 is 6, and dividing both by 6 gives 3/4. A fraction is in lowest terms when the numerator and denominator share no common factor other than 1. Forms like 6/8 and 9/12 are equal in value but not fully reduced.

If a car travels 180 miles in 3 hours, what is its average speed?

• a.540 mph
• b.63 mph
• c.50 mph
• d.60 mph✓

Average speed equals distance divided by time: 180 ÷ 3 = 60 miles per hour. This uses the relationship speed = distance/time. The units confirm the answer is in miles per hour.

What is the mean (average) of 4, 8, 10, and 14?

• a.36
• b.10
• c.8
• d.9✓

Add the numbers to get 36, then divide by the count of 4, giving 9. The mean is the sum of values divided by how many values there are. The total, 36, is not the average itself.

Solve for y: y/4 = 9.

• a.5
• b.36✓
• c.13
• d.2.25

Multiply both sides by 4 to undo the division, giving y = 36. Since y divided by 4 equals 9, y must be 4 times 9. Checking: 36 ÷ 4 = 9, which is correct.

A shirt originally costs $40 and is on sale for 25% off. What is the sale price?

• a.$30✓
• b.$10
• c.$15
• d.$35

A 25% discount on $40 is $10, so the sale price is $40 − $10 = $30. You can also multiply $40 by 0.75 to get $30 directly. The discount is subtracted from the original price.

What is the slope of the line passing through the points (1, 2) and (3, 8)?

• a.6
• b.4
• c.3✓
• d.2

Slope equals the change in y over the change in x: (8 − 2) / (3 − 1) = 6/2 = 3. Slope measures how steep a line is. A positive slope means the line rises from left to right.

The ratio of boys to girls in a class is 3:5. If there are 24 students, how many are girls?

• a.12
• b.9
• c.15✓
• d.18

The ratio 3:5 has 8 parts total, so each part equals 24 ÷ 8 = 3 students. Girls make up 5 parts: 5 × 3 = 15. Ratios divide a whole into proportional shares.

What is 3/4 written as a decimal?

• a.0.75✓
• b.0.34
• c.1.33
• d.0.43

Dividing the numerator 3 by the denominator 4 gives 0.75. A fraction represents division of the top number by the bottom number. This is a common fraction-to-decimal conversion.

A circle has a radius of 6 cm. What is its circumference? (Use π ≈ 3.14.)

• a.18.84 cm
• b.37.68 cm✓
• c.113.04 cm
• d.12 cm

Circumference equals 2πr: 2 × 3.14 × 6 = 37.68 cm. The radius is the distance from center to edge. Using the area formula πr² would instead give about 113 cm².

Evaluate the expression 5(x − 2) when x = 6.

• a.20✓
• b.28
• c.10
• d.40

Substitute x = 6 to get 5(6 − 2) = 5(4) = 20. Following order of operations, solve inside the parentheses first, then multiply. Substituting values into expressions is a key algebra skill.

What is the next number in the pattern: 3, 6, 12, 24, ___?

• a.48✓
• b.30
• c.72
• d.36

Each term is double the one before it, so 24 × 2 = 48. Recognizing that the pattern multiplies by 2 reveals the rule. This is a geometric sequence.

A recipe needs 2 cups of flour for 12 cookies. How many cups are needed for 30 cookies?

• a.2.5 cups
• b.4 cups
• c.5 cups✓
• d.6 cups

Set up a proportion: 2/12 = x/30, so x = (2 × 30)/12 = 5 cups. Proportions keep the ratio of flour to cookies constant. Scaling recipes uses this direct relationship.

What is the area of a triangle with a base of 10 cm and a height of 6 cm?

• a.24 cm²
• b.30 cm²✓
• c.16 cm²
• d.60 cm²

Area of a triangle is one-half the base times the height: (1/2)(10)(6) = 30 cm². The factor of one-half distinguishes a triangle from a rectangle of the same base and height. Area is measured in square units.

Solve the inequality: 2x − 3 < 7.

• a.x > 5
• b.x < 2
• c.x < 5✓
• d.x < 10

Add 3 to both sides to get 2x < 10, then divide by 2 to get x < 5. When dividing an inequality by a positive number, the direction of the sign stays the same. The solution is all values less than 5.

What is 0.6 written as a percent?

• a.0.6%
• b.600%
• c.6%
• d.60%✓

To convert a decimal to a percent, multiply by 100, so 0.6 becomes 60%. This moves the decimal point two places to the right. Percent means 'out of one hundred.'

A box contains 3 red, 4 blue, and 5 green marbles. What is the probability of drawing a blue marble at random?

• a.1/2
• b.1/4
• c.5/12
• d.1/3✓

Probability is favorable outcomes over total outcomes. There are 4 blue marbles out of 3 + 4 + 5 = 12, so the probability is 4/12, which reduces to 1/3. The 1/4 figure is the probability of drawing a red marble (3 out of 12), and 5/12 is the probability of drawing a green one — both are answers to a question that was not asked. And 1/2 would require six blue marbles rather than four.

If 5 pencils cost $1.25, how much do 8 pencils cost at the same rate?

• a.$1.85
• b.$1.60
• c.$2.00✓
• d.$2.50

Each pencil costs $1.25 ÷ 5 = $0.25, so 8 pencils cost 8 × $0.25 = $2.00. Finding the unit rate lets you scale to any quantity. Unit pricing is a common real-world calculation.

What is the value of the expression -4 + 9 − 3?

• a.2✓
• b.10
• c.8
• d.-10

Working left to right: -4 + 9 = 5, and 5 − 3 = 2. Adding a positive to a negative moves toward zero and beyond. Careful sign handling gives the correct result of 2.

A square has a perimeter of 36 cm. What is the length of one side?

• a.12 cm
• b.9 cm✓
• c.18 cm
• d.6 cm

A square has four equal sides, so divide the perimeter by 4: 36 ÷ 4 = 9 cm. Perimeter is the total distance around a shape. Each side of this square measures 9 cm.

Which value of x makes the equation 2x = 5x − 12 true?

• a.6
• b.4✓
• c.3
• d.2

Subtract 2x from both sides to get 0 = 3x − 12, then add 12 and divide by 3 to find x = 4. Gathering variables on one side isolates x. Checking: 2(4) = 8 and 5(4) − 12 = 8, which matches.

The temperature rose from -5°F to 12°F. By how many degrees did it rise?

• a.17°F✓
• b.12°F
• c.7°F
• d.-17°F

The change equals 12 − (−5) = 12 + 5 = 17 degrees. Subtracting a negative is the same as adding its positive. The temperature climbed 17°F.

What is 3/5 + 1/5?

• a.4/5✓
• b.2/5
• c.3/25
• d.4/10

When fractions share a denominator, add the numerators: 3 + 1 = 4, giving 4/5. The denominator stays the same at 5. This result is already in lowest terms.

A phone plan costs $30 per month plus $0.10 per text. Which expression gives the total monthly cost for t texts?

• a.30 + 0.10t✓
• b.30t + 0.10
• c.30.10t
• d.30 + 0.10 + t

The $30 fee is charged once whatever happens, so it stands alone; the 10 cents is charged per text, so it is multiplied by the number of texts. That gives 30 + 0.10t. Writing 30t + 0.10 swaps the two roles, charging $30 per text and a flat dime a month. Writing 30 + 0.10 + t adds the number of texts to the money instead of multiplying, which mixes a count with dollars. And 30.10t charges the whole $30.10 for every single text.

What is the median of the data set 7, 3, 9, 5, 11?

• a.35
• b.5
• c.9
• d.7✓

First order the numbers: 3, 5, 7, 9, 11; the middle value is 7. The median is the center of an ordered list. With five values, the third number is the median.

If a triangle has angles measuring 40° and 75°, what is the third angle?

• a.75°
• b.55°
• c.65°✓
• d.115°

The angles of a triangle sum to 180°, so 180 − 40 − 75 = 65°. This triangle-angle-sum rule holds for every triangle. The missing angle measures 65 degrees.

Expand the expression 4(2x + 3).

• a.6x + 7
• b.8x + 12✓
• c.8x + 7
• d.8x + 3

Use the distributive property to multiply 4 by each term: 4 × 2x = 8x and 4 × 3 = 12. The result is 8x + 12. Distribution multiplies the outside factor across everything inside the parentheses.

A worker earns $18 per hour and works 35 hours in a week. What are the weekly earnings?

• a.$720
• b.$53
• c.$530
• d.$630✓

Multiply the hourly rate by hours worked: 18 × 35 = 630 dollars. Total pay equals rate times time. The worker earns $630 that week.

What is the square root of 144?

• a.11
• b.72
• c.12✓
• d.14

The square root of 144 is the number that, multiplied by itself, gives 144; that number is 12 because 12 × 12 = 144. Square roots reverse the squaring operation. Note that 72 is half of 144, not its root.

A number increased by 20% becomes 60. What was the original number?

• a.48
• b.50✓
• c.40
• d.72

If the original number is x, then 1.20x = 60, so x = 60 ÷ 1.20 = 50. Increasing by 20% multiplies by 1.20. Reversing the increase means dividing by 1.20.

Two angles are complementary. If one measures 35°, what is the other?

• a.45°
• b.145°
• c.55°✓
• d.65°

Complementary angles add up to 90°, so the other angle is 90 − 35 = 55°. Complementary differs from supplementary, which sums to 180°. The missing angle is 55 degrees.

Which part of a plant cell captures light energy for photosynthesis?

• a.Cell wall
• b.Ribosome
• c.Nucleus
• d.Chloroplast✓

Chloroplasts contain chlorophyll, the pigment that absorbs sunlight to power photosynthesis. The nucleus stores genetic material, and ribosomes build proteins. Photosynthesis converts light energy into chemical energy stored in sugars.

What is the chemical formula for water?

• a.H2O✓
• b.O2
• c.CO2
• d.NaCl

Water is made of two hydrogen atoms and one oxygen atom, giving the formula H2O. CO2 is carbon dioxide and NaCl is table salt. Chemical formulas show the types and numbers of atoms in a molecule.

In a food chain, organisms that make their own food using sunlight are called—

• a.decomposers
• b.producers✓
• c.predators
• d.consumers

Producers, such as green plants, make their own food through photosynthesis and form the base of a food chain. Consumers eat other organisms, and decomposers break down dead matter. Energy flows from producers to consumers.

Which gas do humans need to breathe in to survive?

• a.Nitrogen
• b.Carbon dioxide
• c.Hydrogen
• d.Oxygen✓

Humans inhale oxygen, which cells use to release energy from food through respiration. We exhale carbon dioxide as a waste product. Although nitrogen is the most abundant gas in air, the body does not use it for respiration.

A scientist records that a substance boils at 100°C at sea level. Boiling point is an example of a—

• a.chemical formula
• b.chemical change
• c.living factor
• d.physical property✓

Boiling point is a physical property because it can be measured without changing the substance's identity. A chemical change would produce a new substance. Physical properties include color, density, and melting point.

Which of the following best describes the function of the heart?

• a.It produces digestive enzymes.
• b.It filters waste from the blood.
• c.It pumps blood around the body.✓
• d.It controls breathing rate.

The heart is a muscular pump, and circulating blood is the whole of its job: it moves oxygen and nutrients out to the tissues and carries waste away. Filtering waste from the blood is the kidneys' work. Producing digestive enzymes is done by the pancreas and the glands of the gut. And breathing rate is set by the brainstem, not by the heart, although the two adjust together during exercise.

What force pulls objects toward the center of the Earth?

• a.Gravity✓
• b.Friction
• c.Electricity
• d.Magnetism

Gravity is the force that attracts objects toward Earth's center, giving them weight. Friction resists motion between surfaces, and magnetism acts on certain metals. Gravity keeps us and objects on the ground.

A trait passed from parents to offspring through genes is called—

• a.an instinct
• b.a learned behavior
• c.an inherited trait✓
• d.an adaptation

Inherited traits, such as eye color, are passed genetically from parents to offspring. Learned behaviors are acquired through experience, not genes. Genes carry the instructions that determine inherited characteristics.

During the water cycle, what process turns liquid water into water vapor?

• a.Precipitation
• b.Condensation
• c.Evaporation✓
• d.Collection

Evaporation is the change of liquid water into vapor, usually driven by heat from the sun. Condensation is the reverse, forming clouds, and precipitation returns water as rain or snow. Evaporation moves water into the atmosphere.

Which of these is a renewable energy source?

• a.Natural gas
• b.Solar power✓
• c.Petroleum
• d.Coal

Solar power comes from sunlight, which is replenished continuously, making it renewable. Coal, natural gas, and petroleum are fossil fuels that take millions of years to form and can be used up. Renewable sources do not run out on a human timescale.

The smallest unit of life capable of carrying out all life processes is the—

• a.atom
• b.cell✓
• c.molecule
• d.organ

The cell is the basic structural and functional unit of all living things. Atoms and molecules are smaller but are not themselves alive. Organs are made of many cells working together.

A study finds that a group of plants given fertilizer grew taller than plants without it. In this experiment, fertilizer is the—

• a.conclusion
• b.control group
• c.independent variable✓
• d.dependent variable

The independent variable is the factor the scientist deliberately changes; here it is the fertilizer. The plant height that responds is the dependent variable. Well-designed experiments change only one variable at a time.

Which planet is closest to the Sun?

• a.Jupiter
• b.Venus
• c.Earth
• d.Mercury✓

Mercury is the innermost planet, orbiting nearer the Sun than any other. Venus is the second planet out and Earth the third, which is why both are common wrong picks. Jupiter is the fifth planet and far beyond all of them. Distance from the Sun drives a planet's temperature and the length of its year.

When wood burns, it turns to ash and gas. This is an example of a—

• a.chemical change✓
• b.reversible change
• c.physical change
• d.change of state

Burning is a chemical change because new substances, such as ash and gases, form and cannot easily be turned back into wood. Physical changes, like melting, do not create new substances. Chemical changes rearrange atoms into different compounds.

What do we call the variety of living organisms in an ecosystem?

• a.Community
• b.Climate
• c.Population
• d.Biodiversity✓

Biodiversity is the range of different species living in an area. A community is all the populations living together in that area — a related idea, but it names the assemblage rather than its variety. A population is a single species, so it cannot describe variety at all. And climate describes long-term weather patterns, not living things. High biodiversity tends to make an ecosystem more stable.

The process by which a species changes over many generations in response to its environment is called—

• a.condensation
• b.circulation
• c.digestion
• d.evolution✓

Evolution is the gradual change in inherited traits of a population over generations, often through natural selection. It explains how species adapt to their environments over long periods. Individuals do not evolve; populations do.

Which type of blood vessel carries blood away from the heart?

• a.Capillaries
• b.Nerves
• c.Veins
• d.Arteries✓

An artery is defined by direction: it carries blood away from the heart. Note that this is about direction and not oxygen — the pulmonary arteries carry oxygen-poor blood from the heart to the lungs, which is the exception that shows what the definition really rests on. Veins run the other way, returning blood to the heart. Capillaries are the fine vessels between the two where gases and nutrients are exchanged with the tissues. Nerves carry electrical signals and are not blood vessels at all.

A graph shows a town's average temperature rising steadily each decade. This trend best supports the idea of—

• a.climate change✓
• b.seasonal change
• c.daily weather
• d.an eclipse

A steady rise held across decades is a climate signal, because climate is precisely the long-run pattern rather than any single reading. Daily weather is the wrong timescale — it swings far more than this in a single afternoon. Seasonal change is also the wrong timescale, and it repeats each year instead of trending in one direction. And an eclipse is a brief astronomical event with no bearing on a decades-long temperature record.

Which of the following is a chemical property of a substance?

• a.Its density
• b.Its ability to rust✓
• c.Its hardness
• d.Its boiling point

Rusting is iron reacting with oxygen to form a new substance, so the ability to rust describes how the material behaves chemically. Density, hardness and boiling point can all be measured without turning the substance into anything else, which is exactly what makes them physical properties. The dividing line is whether observing the property destroys the original substance: weigh it, scratch it or boil it and you still have the same material, but rust it and you do not.

In the human body, which system is responsible for breaking down food into nutrients?

• a.Respiratory system
• b.Nervous system
• c.Digestive system✓
• d.Skeletal system

The digestive system breaks food down into nutrients the body can absorb and use. The respiratory system handles gas exchange, and the nervous system sends signals. Digestion begins in the mouth and continues through the stomach and intestines.

Which of these best explains why ice floats on water?

• a.Ice is less dense than water.✓
• b.Ice contains more salt than water.
• c.Ice has more mass than water.
• d.Ice is warmer than water.

Water is unusual: as it freezes its molecules lock into an open lattice that takes up more room than the liquid, so a given mass of ice occupies more volume and is therefore less dense. Anything less dense than the fluid around it floats. Ice does not contain more salt than the water it forms from — freezing tends to exclude salt. Having more mass is irrelevant without knowing volume, since density is mass per unit volume. And ice is colder than liquid water, not warmer.

Bacteria that break down dead plants and animals are known as—

• a.producers
• b.herbivores
• c.decomposers✓
• d.predators

Decomposers, including many bacteria and fungi, break down dead organisms and return nutrients to the soil. This recycling supports new plant growth. Without decomposers, dead matter and nutrients would accumulate unused.

A meteorologist predicts rain based on falling air pressure. Air pressure is measured with a—

• a.thermometer
• b.barometer✓
• c.telescope
• d.anemometer

A barometer measures air pressure, which helps forecast weather changes. A thermometer measures temperature and an anemometer measures wind speed. Falling air pressure often signals approaching storms.

Which statement correctly describes an atom?

• a.It is the smallest unit of a compound.
• b.It is a particle found only in metals.
• c.It is the smallest living thing.
• d.It is the smallest unit of an element.✓

An atom is the smallest particle of an element that still has that element's properties. The smallest unit of a compound is a molecule, not an atom, which is the near-miss worth learning. Atoms are not confined to metals — every element, including the gases you are breathing, is made of them. And the smallest living thing is a cell, which is built from enormous numbers of atoms and is a different order of thing entirely.

The energy stored in food is a form of—

• a.chemical energy✓
• b.light energy
• c.sound energy
• d.kinetic energy

Food stores chemical energy in the bonds of its molecules, which the body releases during digestion and respiration. Kinetic energy is energy of motion. Cells convert this chemical energy into usable forms to power life processes.

Which action would most reduce the amount of waste sent to landfills?

• a.Sending yard waste to the landfill
• b.Recycling paper, glass, and plastic✓
• c.Buying products with extra packaging
• d.Using more disposable items

Recycling diverts paper, glass and plastic out of the waste stream and back into manufacturing, so the material never reaches the landfill at all. Sending yard waste there does the opposite: it is organic matter that could be composted, and it adds directly to landfill volume. Buying products with extra packaging increases waste before the item is even used. And using more disposable items replaces things that would have been reused, which raises the volume thrown away.

A scientist repeats an experiment several times and gets similar results. This repetition mainly helps to—

• a.change the independent variable
• b.make the results more reliable✓
• c.prove the hypothesis is a law
• d.eliminate the need for a control

Repeating an experiment and getting consistent results makes the findings more reliable and trustworthy. Repetition helps rule out chance errors. Reliable, reproducible data is a cornerstone of the scientific method.

Which document begins with the words 'We the People' and establishes the framework of the U.S. government?

• a.The U.S. Constitution✓
• b.The Bill of Rights
• c.The Emancipation Proclamation
• d.The Declaration of Independence

The U.S. Constitution opens with 'We the People' and sets up the structure of the federal government. The Declaration of Independence announced separation from Britain. The Bill of Rights is the first ten amendments to the Constitution.

The U.S. government is divided into three branches. Which branch makes the laws?

• a.Legislative✓
• b.Executive
• c.Judicial
• d.Military

The legislative branch, Congress, makes the laws. The executive branch enforces them and the judicial branch interprets them. This separation of powers prevents any one branch from becoming too strong.

What is the main purpose of the Bill of Rights?

• a.To list the duties of the president
• b.To declare war on Britain
• c.To protect individual freedoms✓
• d.To set tax rates

The Bill of Rights, the first ten amendments, protects individual liberties such as free speech and religion. It limits the power of the federal government over citizens. These protections were added to gain support for ratifying the Constitution.

In an economy, what does the term 'supply' refer to?

• a.The tax on a product
• b.The total money in a bank
• c.The desire of consumers to buy a good
• d.The quantity producers offer for sale✓

Supply is the quantity of a good producers are willing to offer at a given price. The desire of consumers to buy is demand, the other half of the pair, and confusing the two reverses every prediction you would make about price. The total money in a bank is a measure of deposits and has nothing to do with the market for a particular good. And a tax on a product shifts supply but is not itself supply.

Which right is protected by the First Amendment?

• a.The right to a speedy trial
• b.Protection from unreasonable searches
• c.Freedom of speech✓
• d.The right to bear arms

The First Amendment protects freedoms of speech, religion, press, assembly, and petition. The right to bear arms is in the Second Amendment. Knowing which amendment covers which right is a core civics concept.

The American Civil War (1861-1865) was fought largely over which issue?

• a.Trade with China
• b.Women's right to vote
• c.Independence from Britain
• d.Slavery and its expansion✓

The war followed decades of conflict over slavery and, above all, over whether it would spread into the western territories; the seceding states said so in their own declarations of causes. Independence from Britain was the Revolutionary War, roughly eighty years earlier. Women's suffrage was a separate nineteenth- and twentieth-century movement that culminated in 1920. And trade with China had no bearing on secession.

What is inflation?

• a.A drop in the population
• b.A type of government tax
• c.An increase in exports only
• d.A general rise in prices✓

Inflation is a sustained rise in the overall price level, which means each dollar buys less than it did. The word 'general' is doing the work: one product getting dearer is not inflation. A tax is a government charge, not a movement in prices, though taxes can feed into them. A drop in population is a demographic change with no direct definition in terms of prices. And a rise in exports alone describes trade, not the price level.

Which body of water borders the United States on the west coast?

• a.The Indian Ocean
• b.The Atlantic Ocean
• c.The Pacific Ocean✓
• d.The Gulf of Mexico

The Pacific Ocean lies along the western coast of the United States, bordering states like California and Oregon. The Atlantic Ocean is on the east coast. Basic map knowledge helps interpret geography questions.

In the United States, how often are presidential elections held?

• a.Every four years✓
• b.Every six years
• c.Every year
• d.Every two years

Presidential elections occur every four years, as set by the Constitution. Members of the House serve two-year terms and senators serve six-year terms. Regular elections are a key feature of representative democracy.

What was the main goal of the Civil Rights Movement of the 1950s and 1960s?

• a.To end legal racial segregation✓
• b.To lower federal taxes
• c.To end U.S. involvement in wars
• d.To expand the railroad system

The movement of the 1950s and 1960s set out to dismantle legally enforced racial segregation and the disfranchisement that went with it, producing the Civil Rights Act of 1964 and the Voting Rights Act of 1965. Lowering federal taxes belongs to a different political tradition altogether. Ending U.S. involvement in wars describes the antiwar movement, which overlapped in time but not in aim. And expanding the railroad system was a nineteenth-century project, roughly a century early.

A map's scale is used to—

• a.label the capital cities
• b.show real distances✓
• c.show the direction of north
• d.indicate elevation with color

A scale tells you what a distance on the page is worth on the ground, which is what lets you turn two inches of map into miles. Direction is the compass rose's job, not the scale's. Capital cities are marked by symbols in the legend. And elevation shown through color is a feature of a relief or topographic map, again read from the legend rather than the scale.

Which economic system is based on private ownership and market competition?

• a.Communism
• b.Feudalism
• c.Monarchy
• d.Capitalism✓

Capitalism is an economic system in which individuals and businesses privately own property and compete in markets. Prices are largely set by supply and demand. This contrasts with communism, where the state controls production.

The Declaration of Independence (1776) was written primarily to—

• a.establish the three branches of government
• b.justify separation from Britain✓
• c.abolish slavery
• d.create the Supreme Court

The Declaration set out the colonies' reasons for breaking with British rule, resting them on natural rights and government by consent. It established no institutions: the three branches were created by the Constitution eleven years later, and the Supreme Court with them. And it did not abolish slavery — that came with the Thirteenth Amendment in 1865, nearly ninety years afterward.

What is the role of the U.S. Supreme Court?

• a.To command the armed forces
• b.To collect federal taxes
• c.To interpret the Constitution✓
• d.To write new laws

The Court interprets the Constitution and decides whether laws square with it, the power known as judicial review. Writing new laws is Congress's job, and a court that wrote them would collapse the separation of powers the Constitution sets up. Commanding the armed forces belongs to the President as commander in chief. And collecting federal taxes is an executive function carried out by the Treasury.

Which term describes goods a country sells to other countries?

• a.Exports✓
• b.Subsidies
• c.Imports
• d.Tariffs

Exports are goods and services a country sells to other nations. Imports are what a country buys from abroad. The balance between exports and imports affects a nation's trade relationships.

The idea that government power comes from the consent of the people is called—

• a.isolationism
• b.nationalism
• c.popular sovereignty✓
• d.federal supremacy

Popular sovereignty is the principle that a government's authority comes from the people it governs, which is why the Constitution opens 'We the People.' Federal supremacy is about which level of government prevails in a conflict, not about where authority originates. Nationalism concerns loyalty to a nation, which says nothing about who authorizes the government. And isolationism is a foreign-policy stance about staying out of other nations' affairs.

Which invention of the Industrial Revolution most changed how goods were manufactured?

• a.The steam engine✓
• b.The compass
• c.The printing press
• d.The telescope

The steam engine powered factories and machines, greatly increasing production during the Industrial Revolution. It also transformed transportation through trains and steamships. This shift moved economies from handmade goods to mass production.

A tax placed on imported goods is called a—

• a.dividend
• b.surplus
• c.subsidy
• d.tariff✓

A tariff is a tax on imported goods, often used to protect domestic industries or raise revenue. Tariffs raise the price of foreign products. A subsidy, by contrast, is government support given to producers.

Which of these is a responsibility of U.S. citizens?

• a.Joining a political party
• b.Owning a business
• c.Traveling abroad
• d.Serving on a jury✓

Jury service is a duty: when you are summoned you must appear, and that obligation is what makes it a responsibility rather than a choice. Joining a political party, traveling abroad and owning a business are all things a citizen may do and none that a citizen must do. The test is whether the law can require it of you.

The Great Depression of the 1930s was mainly a period of—

• a.westward pioneer settlement
• b.mass unemployment and poverty✓
• c.military expansion abroad
• d.rapid economic growth

The 1930s brought bank failures, collapsing output and unemployment that reached roughly a quarter of the workforce at its worst, which is what the New Deal programs were built to answer. Rapid economic growth is the exact opposite and describes the 1920s that preceded it. Westward pioneer settlement had largely ended decades earlier. And large-scale military expansion abroad came afterward, with the Second World War.

On a political map, boundary lines usually show—

• a.population density
• b.political borders✓
• c.ocean currents
• d.mountain ranges

A political map's job is to show how territory is divided among governments, so its lines mark the borders of countries, states and provinces. Mountain ranges and other natural features belong to a physical map, which is the contrast worth holding onto. Population density is shown by a thematic map, usually through shading. And ocean currents appear on specialized maps with arrows, not as boundary lines.

Which document divides government power between the national and state governments, a system called federalism?

• a.The Monroe Doctrine
• b.The Gettysburg Address
• c.The U.S. Constitution✓
• d.The Mayflower Compact

The U.S. Constitution establishes federalism by dividing powers between the national and state governments. Some powers are shared, while others belong to one level. This balance prevents overly concentrated authority.

What generally happens to the price of a good when demand rises but supply stays the same?

• a.The price stays exactly the same
• b.The price tends to fall
• c.The price tends to rise✓
• d.The good becomes free

When demand increases while supply is unchanged, competition among buyers usually pushes the price up. This reflects the basic law of supply and demand. Higher demand with limited supply raises prices.

The right of citizens to vote is known as—

• a.suffrage✓
• b.taxation
• c.federalism
• d.immigration

Suffrage is the right to vote in elections. Over U.S. history, suffrage expanded to include women in 1920 and was strengthened for racial minorities in the 1960s. Voting is a fundamental way citizens influence government.

Which level of government is primarily responsible for public schools and local police?

• a.State and local✓
• b.Federal government
• c.Foreign governments
• d.The Supreme Court

Schools and municipal police are funded and run at the state and local level, which is why school policy and policing differ so sharply from one town to the next. The federal government takes the matters that have to be uniform across the country, such as defense and foreign policy. The Supreme Court decides cases and administers no public service at all. And foreign governments have no role in either.

A primary source in the study of history is best described as—

• a.a textbook written today about the past
• b.an encyclopedia summary
• c.a firsthand record from the time studied✓
• d.a modern documentary film

A primary source was created during the period under study by someone who was there — a letter, a diary, a photograph, a law as enacted. A textbook written today, an encyclopedia entry and a modern documentary are all secondary: they interpret the period afterward, using primary sources as their raw material. The question is always when the source was made and by whom, not how reliable it is.

The system in which citizens elect representatives to make decisions on their behalf is called—

• a.an absolute monarchy
• b.a representative democracy✓
• c.a military dictatorship
• d.a direct democracy

In a representative democracy the people choose officials who then make decisions for them, which is how the U.S. Congress and state legislatures work. A direct democracy is the close comparison and the one to keep separate: there the citizens vote on the measures themselves rather than electing anyone to do it. An absolute monarchy vests power in a hereditary ruler, and a military dictatorship in the armed forces — in neither case does an election decide who governs.

Read: 'City buses ran every ten minutes during the strike. Ridership rose by a third. When normal service returned, the buses came every twenty minutes again and ridership fell back.' The main idea of this passage is that—

• a.the city should hire more bus drivers
• b.strikes are good for public transit
• c.more frequent service attracts more riders✓
• d.bus riders dislike waiting in the cold

Every sentence links how often buses came to how many people rode them, and the passage rises and falls with that one relationship, which is what makes it the main idea. Nothing here praises strikes; the strike is only the occasion that changed the schedule. Cold weather is never mentioned. And hiring more drivers is a recommendation the passage does not make.

Read: 'The new library opened in March. Within a month, card applications had tripled.' The second sentence functions mainly to—

• a.give a result of what the first sentence describes✓
• b.offer an opinion about the new library
• c.flatly contradict the claim made in the first sentence
• d.define a technical term that the first sentence used

The tripling is presented as what followed from the opening, so the second sentence supplies the outcome. It does not contradict anything; the two sit comfortably together. No term in the first sentence is defined. And the sentence gives a number rather than a judgment, which is what keeps it out of the realm of opinion.

Read: 'Sleep researchers once treated naps as a sign of laziness. Recent studies suggest a short afternoon nap improves alertness and memory.' The organizational pattern here is—

• a.a description of how a physical process unfolds
• b.a list of the steps in a standard research method
• c.contrast between an older view and a newer one✓
• d.a story told in the order it happened

The passage sets an earlier belief against later findings, and the word 'once' against 'recent' is the hinge. No procedure is laid out step by step. Nothing describes how a process physically unfolds. And there is no narrative here, only two positions placed side by side.

Read: 'The manual warns that the blade must be locked before the housing is closed. Skipping this step has caused several injuries.' The author's purpose is mainly to—

• a.compare two brands of equipment
• b.warn readers about a specific danger✓
• c.entertain readers with a workplace story
• d.persuade readers to buy a safer model

The passage names a required step and states the harm that follows from omitting it, which is the shape of a safety warning. It tells no story and is not written to amuse. No product is being recommended for purchase. And only one piece of equipment appears, so nothing is being compared.

Read: 'The proposal is ambitious, expensive, and, if the last three attempts are any guide, unlikely to survive its first winter.' The tone of this sentence is best described as—

• a.neutral
• b.enthusiastic
• c.skeptical✓
• d.apologetic

The writer grants the proposal's ambition and then undercuts it with a prediction of failure drawn from past attempts, which is doubt rather than approval. Enthusiasm would not raise the record of three failures. A neutral report would give the details without the closing verdict. And nothing here offers an apology for anything.

Read: 'The negotiations collapsed when the smaller union walked out. Its members had been promised a vote on the contract and never received one.' The second sentence mainly—

• a.explains why the walkout happened✓
• b.predicts what the union will do next
• c.summarizes the contract's main terms
• d.questions whether the walkout occurred

The broken promise is offered as the cause of the walkout announced in the first sentence, so the second supplies the reason. Nothing is predicted about the future. The walkout is treated as a fact, not doubted. And the contract's terms are never described.

Read: 'Few applicants had any formal training. Nevertheless, the shop hired eleven of them and trained them itself.' The word 'nevertheless' signals—

• a.a conclusion drawn from evidence
• b.a step following in sequence
• c.an example of what came before
• d.a contrast with what came before✓

'Nevertheless' introduces something that happens in spite of the preceding statement, so it marks contrast. An example would be signaled by a phrase such as 'for instance.' A conclusion would be signaled by 'therefore' or 'so.' And a sequence would use 'next' or 'then.'

Read: 'The report was exhaustive: four hundred pages, nine appendices, and an index that ran to thirty pages by itself.' In this sentence, 'exhaustive' means—

• a.extremely thorough✓
• b.unusually brief
• c.poorly organized
• d.physically tiring

The details after the colon are all measures of extent, and they define the word by illustrating it: the report leaves nothing out. 'Exhausting' would mean tiring, but that is a different word doing a different job. Nothing in the sentence suggests disorder; an index of that length suggests the opposite. And brevity is plainly the opposite of what is described.

Read: 'By the third week the kitchen ran like a clock: every pan in its place, every order out in six minutes.' The phrase 'ran like a clock' is—

• a.a quotation from another writer
• b.a literal statement about a timepiece
• c.a simile describing smooth operation✓
• d.an exaggeration meant to be doubted

The comparison uses 'like' to liken the kitchen's regularity to a clock's, which is a simile, and the details that follow spell out what the comparison means. The kitchen is not a clock, so the statement is not literal. It is not an exaggeration the reader is meant to reject; the six-minute detail supports it. And nothing marks the phrase as borrowed from another author.

Read: 'I had promised myself I would not look back at the house. At the corner I looked back anyway, and the porch light was still on.' The passage is told from—

• a.an omniscient point of view
• b.the second-person point of view
• c.the first-person point of view✓
• d.the third-person limited point of view

The narrator uses 'I' and reports her own promise and her own failure to keep it, which is first person. Third-person limited would use 'she' while staying inside one character's mind. Second person would address the reader as 'you.' And an omniscient narrator would move among several characters' thoughts.

Read: 'He set the cup down without drinking, straightened the napkin twice, and asked again what time the train left.' These details mainly reveal that the character is—

• a.anxious✓
• b.exhausted
• c.angry
• d.cheerful

Untouched coffee, fussing with a napkin and repeating a question are small restless acts, and together they read as nerves. Exhaustion would show as stillness or heaviness rather than fidgeting. Nothing in the behavior suggests good humor. And anger usually shows in sharper action or speech than straightening a napkin.

Read: 'The apartment was cheap because the train passed ten feet from the bedroom window. She had stopped hearing it by October.' What does the second sentence suggest?

• a.She moved to a new apartment
• b.Her hearing had been damaged
• c.The trains stopped running
• d.She grew used to the noise✓

Ceasing to notice a constant sound is the ordinary meaning of getting used to it, and the date marks how long it took. Nothing indicates the trains stopped; the rent had already been set by them. No move is mentioned. And reading the line as hearing loss takes a common idiom far more literally than the passage invites.

Read: 'Two clerks handled every claim by hand. After the new system arrived, one clerk handled four times as many, and the backlog that had taken months cleared in three weeks.' Which detail best supports the idea that the new system was effective?

• a.The months-long backlog cleared in three weeks✓
• b.Two clerks had handled the claims by hand
• c.A new system was installed at the office
• d.Claims had to be handled one at a time

The backlog figure compares before and after directly and is the only number that measures the result. The two clerks and the manual handling describe the old arrangement, which is the problem rather than the evidence. That a system arrived is the event, not proof it worked. And handling claims one at a time is a description of method.

Read: 'Most guides say to water a fern twice a week. Ferns in dry indoor air often need more, and the surest test is the soil rather than the calendar.' The writer's attitude toward the standard advice is—

• a.that it is completely mistaken
• b.that it is a rough guide, not a rule✓
• c.that it applies mainly outdoors
• d.that it is the only safe method

The passage does not reject the twice-a-week figure; it offers a better test and says the figure often falls short, which treats it as approximate. Calling it completely mistaken is stronger than anything written. Nothing presents it as the only safe method, since an alternative is recommended. And the passage is about indoor air, not a contrast with outdoors.

Read: 'Pumice is light enough to float. It forms when frothy lava cools so fast that the gas bubbles are trapped inside the rock.' The relationship between the two sentences is that the second—

• a.restates what the first sentence says in other words
• b.explains the cause of what the first states✓
• c.questions the accuracy of the first
• d.gives a particular example of what the first states

Trapped gas bubbles are why the rock is light enough to float, so the second sentence supplies the cause of the property named in the first. An example would be a particular instance of floating pumice. A restatement would repeat the same fact differently. And nothing casts doubt on the first sentence.

Read: 'The article lists the mayor's spending on parks, on street repair, and on the new transit center, then asks where the money for schools went.' The article's structure is best described as—

• a.a set of instructions
• b.a chronological narrative
• c.a comparison of two cities
• d.details leading to a question✓

Three parallel items of spending are laid out and the piece closes by asking what was left out, so the details build toward the question. No sequence of events over time is given. Only one city appears. And nothing directs the reader to do anything.

Read: 'Applicants must submit the form by May 1. Late forms are not reviewed. Applicants who miss the date may apply again in the fall.' The passage is best described as—

• a.informational writing stating a policy✓
• b.a persuasive appeal to applicants
• c.a fictional scene about a deadline
• d.a personal account of applying

The passage states requirements and consequences plainly, which is what a policy notice does. Nothing here argues that the reader should do anything or urges a position. No narrator recounts a personal experience. And there is no scene, character or invented action.

Read: 'The committee met for six hours. It adjourned without a vote, scheduled another meeting, and issued a statement praising the discussion.' The passage implies that the committee—

• a.voted down the proposal
• b.reached a firm agreement
• c.disbanded permanently
• d.made no decision✓

Six hours with no vote and a further meeting scheduled is the picture of an unresolved matter, and the statement praising the discussion says nothing about an outcome. An agreement would have produced a vote or a decision. The new meeting shows the committee continues to exist. And voting a proposal down would itself be a vote, which the passage says did not happen.

Read: 'Every Thursday my grandmother set out three cups, though only two of us ever drank.' The detail of the third cup mainly serves to—

• a.hint at someone who is absent✓
• b.show that the family was wealthy
• c.explain how the tea was prepared
• d.describe the size of the kitchen

A place laid for someone who never comes points the reader toward an absence the narrator does not name, which is why the detail is given at all. A single extra cup says nothing about wealth. The passage describes no preparation. And no dimension of the room is mentioned.

Read: 'The first paragraph of the report defines three terms. The second applies them to last year's figures.' The first paragraph functions as—

• a.background the reader needs✓
• b.a summary of the findings
• c.evidence for a conclusion
• d.the report's main argument

Definitions laid down before the analysis begins prepare the reader to follow it, which is the work of background. The argument comes later, where the terms are applied. Definitions are not evidence, since nothing is being proved by them. And a summary would come after the findings rather than before them.

Read: 'For eleven years the plant had run three shifts. In the spring it ran two, then one, and by August the gate was chained.' The passage conveys a sense of—

• a.gradual decline✓
• b.cheerful change
• c.sudden disaster
• d.steady growth

Three shifts to two to one to none is a sequence of steps downward over months, and the pacing is the point. A sudden disaster would arrive all at once rather than by stages. Growth runs the other way. And nothing in the passage invites a cheerful reading.

Read: 'Both accounts of the fire agree on the time and the address. They differ entirely on who called it in.' A reader should conclude that—

• a.both accounts are equally unreliable throughout
• b.one of the two accounts must be entirely invented
• c.the fire probably never happened
• d.the accounts overlap but conflict on one point✓

The passage says the two agree on some facts and diverge on another, which is exactly a partial overlap with one conflict. A single disagreement does not make either account wholly invented. The agreement on time and place makes the fire more credible, not less. And declaring both equally unreliable ignores everything they agree on.

Read: 'The pay was poor and the hours were worse, and I would take the job again tomorrow.' The effect of the last clause is to—

• a.repeat the earlier complaint
• b.explain how wages were set
• c.reverse the reader's expectation✓
• d.list a third drawback of the job

Two complaints set the reader up to expect a third, and the sentence turns instead to loyalty, which is what makes it land. It repeats nothing. Nothing is said about how the pay was determined. And the clause is not a drawback at all; it is the opposite.

Read: 'A heading in the manual reads TROUBLESHOOTING. Under it, each paragraph opens with a symptom in bold type.' These features help a reader mainly by—

• a.proving the manual is accurate
• b.adding the author's opinions
• c.shortening the manual overall
• d.making information easy to locate✓

A heading and bolded openers let a reader scan for the problem at hand instead of reading the section through, which is what text features are for. Formatting does not establish accuracy. Headings add words rather than removing them. And neither device carries an opinion.

Read: 'The town should repave Mill Road. It carries eight thousand cars a day, and the county logged forty-one pothole complaints there last year.' The writer's claim is—

• a.that eight thousand cars use the road
• b.that Mill Road should be repaved✓
• c.that the county logs pothole complaints
• d.that forty-one complaints were filed

A claim is the position the writer wants accepted, and everything else in the passage is offered to support it. The traffic count and the complaint total are the evidence, not the point being argued. And the fact that the county keeps such a log is background that makes the evidence available.

Read: 'Our cafeteria should stay open until eight. Nearly half of evening students finish class after six, and the nearest market is two miles away.' Which sentence states evidence rather than the claim?

• a.Nearly half of evening students finish after six✓
• b.The cafeteria should stay open until eight
• c.Students deserve a better campus experience
• d.The current closing time is unreasonable

Evidence is a checkable fact offered in support, and the proportion of students finishing late is exactly that. The sentence about staying open until eight is the claim itself. Deserving a better experience is a value judgment. And calling the current hour unreasonable restates the claim in other words.

Read: 'Three of my cousins learned to swim before they were five, so children can obviously learn to swim at any age.' The weakness in this argument is that it—

• a.relies on a definition nobody accepts
• b.quotes a source that does not exist
• c.generalizes from a very small sample✓
• d.attacks the character of an opponent

Three relatives cannot establish what children in general can do, and the word 'obviously' hides how little has been shown. Nobody's character is attacked here. No definition is in dispute. And no source is cited at all, correctly or otherwise.

Read: 'Ice cream sales and drowning deaths both rise in July. Clearly one causes the other.' The flaw in this reasoning is that—

• a.the statistics quoted are almost certainly false
• b.ice cream sales vary by region
• c.two things rising together need not be linked✓
• d.drowning deaths are notoriously hard to count accurately

Both figures rise in hot weather, so a third factor explains the pattern, and treating a correlation as a cause is the error. The passage gives no reason to doubt the figures themselves. Difficulty of counting would weaken the data but is not the flaw shown. And regional variation is beside the point being made.

Read: 'Everyone at the meeting supported the plan, so it must be the right choice.' This argument relies on—

• a.a calculation of the plan's cost
• b.a comparison with a closely similar case from the past
• c.the recorded testimony of an expert who studied the plan
• d.the popularity of a view rather than its merits✓

Agreement among those present says nothing about whether the plan will work, and substituting the count of supporters for reasons is the whole of the argument. No past case is offered. No expert is cited. And no cost appears anywhere in the sentence.

Read: 'You can dismiss her argument about the budget; she has never balanced one in her life.' The problem with this response is that it—

• a.concedes the point it means to deny
• b.depends on a statistic that is outdated
• c.offers too much detail about the budget
• d.attacks the person instead of the argument✓

Whether the speaker has balanced a budget has no bearing on whether her reasoning about this one is sound, and the reply never engages that reasoning. It offers no detail about the budget at all. It concedes nothing. And no statistic, current or stale, is used.

Read: 'Either we cut the arts program or we lay off teachers.' The weakness in this statement is that it—

• a.repeats a point that the other side already conceded
• b.presents only two options when others exist✓
• c.uses figures that cannot be verified anywhere
• d.quotes an opponent out of context

Framing a budget problem as a choice between exactly two painful outcomes shuts out every other possibility, from new revenue to smaller cuts spread across departments. No figures appear in the sentence. Nothing is repeated. And no opponent is quoted.

Read: 'This policy is the best one available because no better policy exists.' This reasoning is weak because it—

• a.assumes what it is supposed to prove✓
• b.cites a source with an interest in the outcome
• c.generalizes from a single unusual case
• d.confuses the order of two events

The reason given restates the conclusion in other words, so the argument goes in a circle and never reaches outside itself for support. No source is named. No case, unusual or otherwise, is offered. And no sequence of events is described.

Which of these is a statement of fact rather than opinion?

• a.The library should open earlier on Tuesdays
• b.The library closed at six on Tuesday✓
• c.The library is the best building in town
• d.The library's hours are far too short

A fact can be checked against a record, and the closing time either was six or it was not. Calling the hours too short is a judgment about what is enough. Naming a building the best is a matter of taste. And saying the library should open earlier recommends an action rather than reporting one.

Read: 'The new brand of paint dried faster in our test than the leading brand.' A reader should ask first—

• a.how heavy each can was
• b.where the paint was purchased
• c.who conducted the test✓
• d.what color the paint was

If the manufacturer ran its own test, the result may still be true but it deserves more scrutiny, so the source is the first question a careful reader asks. Color, weight and place of purchase have no bearing on drying time or on the credibility of the comparison.

Read: 'A survey of twelve neighbors found that most oppose the new parking rule. The city should repeal it.' The clearest weakness is that—

• a.the neighbors were not named
• b.parking rules of this kind are rarely repealed
• c.twelve neighbors cannot speak for the city✓
• d.surveys can never measure public opinion reliably

A dozen people on one street is far too small and too narrow a group to stand for a city's residents, so the evidence does not reach the conclusion. How often rules get repealed says nothing about whether this one should be. Surveys can measure opinion well when the sample is adequate. And naming the respondents would not fix the size of the sample.

Read: 'Some argue that the fee is a burden on small shops. In fact the fee is waived for any business under twenty employees.' The second sentence functions as—

• a.a rebuttal of the stated objection✓
• b.a concession that the objection is right
• c.a restatement of the objection
• d.an example supporting the objection

The writer names an opposing point and then answers it with a fact that removes its force, which is what a rebuttal does. It does not restate the objection, since it introduces new information. It works against the objection rather than illustrating it. And a concession would agree rather than reply.

Read: 'Night classes should be expanded. Enrollment in the two existing sections has been full for six straight terms, and ninety students were turned away last fall.' The evidence supports the claim mainly by showing—

• a.that students prefer evenings to mornings
• b.that demand exceeds the current supply✓
• c.that night classes are taught well
• d.that the college can afford more sections

Full sections and ninety rejected students are measures of unmet demand, which is precisely what an argument for expansion needs. Nothing in the figures speaks to teaching quality. Affordability is a separate question the passage never addresses. And a preference for evenings is not established, since the students turned away may have had no other option.

Read: 'Since the speed limit dropped, crashes on Route 9 have fallen by a fifth.' Which additional fact would most weaken this argument that the lower limit worked?

• a.Most drivers say they support the change
• b.The road was closed for repairs half that year✓
• c.The speed limit fell by ten miles per hour
• d.Crashes rose on a different road nearby

If the road was shut for months, there was less traffic to crash, which supplies an alternative explanation for the drop and undercuts the causal claim. The size of the speed reduction describes the policy rather than testing it. A change on another road does not explain this one. And driver approval is opinion, not evidence about crashes.

Read: 'The program must be working. My neighbor enrolled and found a job within a month.' This argument depends on—

• a.a single story standing in for a pattern✓
• b.a definition that shifts halfway through
• c.a threat about what will happen next
• d.an appeal to an unnamed authority

One person's experience may be encouraging, but it cannot show what a program does in general, and nothing else is offered. No definition is used, let alone changed. No authority is invoked. And nothing is threatened.

Read: 'The measure will save money, improve safety, and, according to the engineers who studied it, cut travel times by nine minutes.' The strongest evidence in this sentence is—

• a.the promise that it will save money
• b.the engineers' estimate of nine minutes✓
• c.the fact that the measure exists
• d.the assurance that safety will improve

A specific figure attributed to people who studied the problem can be examined and challenged, which is what makes it evidence rather than assertion. Saving money and improving safety are stated without any support. And that the measure exists is not evidence for anything.

Read: 'Studies suggest that walking thirty minutes a day may reduce the risk of heart disease.' Compared with a claim that walking prevents heart disease, this statement is—

• a.identical in meaning to the stronger claim
• b.an opinion rather than a report
• c.more cautious and easier to defend✓
• d.stronger and harder to support

The words 'suggest,' 'may' and 'reduce the risk' all limit what is being asserted, which makes the claim easier to back with real findings. A stronger claim would be harder to defend, not this one. The two are not identical: prevention and risk reduction are different claims. And reporting what studies indicate is not a statement of preference.

Read: 'Anyone who cares about children will support this bond measure.' The persuasive technique at work is—

• a.tying the position to the reader's identity✓
• b.defining an unfamiliar technical term
• c.conceding the strongest opposing point
• d.citing the results of a controlled study

The sentence makes disagreement look like not caring about children, so the reader is pressed by self-image rather than by reasons about the bond. No study is cited. No opposing point is granted. And no term is defined.

Read: 'Two writers disagree about the bridge. One cites the repair estimate; the other cites the number of daily crossings.' The disagreement is best described as—

• a.a dispute about what the words in question mean
• b.a difference in which evidence matters most✓
• c.a disagreement about a past event
• d.a case of one of the writers inventing facts

Both writers use real figures; they differ over which consideration should govern the decision, cost or use. Nothing suggests a quarrel over definitions. Nothing indicates either figure is fabricated. And neither is describing an event that already happened.

Read: 'The council's so-called reform hands a windfall to developers.' The phrase 'so-called' mainly—

• a.identifies the reform's official title
• b.signals the writer's disapproval✓
• c.shows the writer is quoting a source
• d.marks a term the reader may not know

Placing 'so-called' before 'reform' tells the reader the writer does not accept the label, which is loaded language doing argumentative work. It does not supply an official name. It is not a quotation. And it is not glossing an unfamiliar word.

Read: 'The clinic treats more patients than any other in the county, and its waiting times are the longest.' A reader who concludes the clinic is poorly run has—

• a.misread what the word county is being used to mean
• b.overlooked that volume can explain the wait✓
• c.assumed that the figures given had been invented
• d.confused the clinic with another one

The same sentence that reports long waits also reports the highest patient volume, which is an obvious alternative explanation the hasty conclusion ignores. The meaning of 'county' is not in question. The figures are taken at face value by both readings. And no confusion of identity is involved.

Read: 'If we allow food trucks downtown, the next thing will be carnival rides on Main Street.' This argument is weak because it—

• a.presents an opinion as a statistic
• b.relies on a source that cannot be checked
• c.uses a word in two different senses
• d.assumes one small step leads to an extreme one✓

Nothing connects permitting food trucks to permitting carnival rides, so the chain is asserted rather than shown, which is the slippery-slope move. No source is mentioned. No word shifts its meaning. And no statistic appears.

Read: 'The company says the layoffs were unavoidable. The union says the company spent forty million on stock buybacks in the same quarter.' The union's response works by—

• a.agreeing with the company's reasoning
• b.predicting what the company will do next
• c.offering a fact that tests the company's claim✓
• d.questioning the meaning of the word layoff

If the money was there for buybacks, the claim that layoffs could not be avoided becomes much harder to sustain, so the figure is a direct challenge. The union is not agreeing. No definition is disputed. And nothing is predicted.

A writer claims that a new bus route would be well used. Which evidence would support that claim most strongly?

• a.A council member's promise to fund the route
• b.Ridership counts from a similar route in the same city✓
• c.A statement that buses are good for the environment
• d.The number of buses the city currently owns

Counts from a comparable route measure the very thing in question, how many people actually ride, and come from the same city. Environmental benefit is a separate argument for the route, not evidence of use. The size of the bus fleet is a capacity fact. And a promise of funding says nothing about ridership.

Read: 'Because the tax was cut in January and hiring rose in June, the tax cut created the jobs.' The argument assumes—

• a.that hiring figures are measured every month
• b.that the tax cut in question was a small one
• c.that nothing else could explain the hiring✓
• d.that January precedes June

The reasoning treats sequence as proof of cause, which only works if every other explanation, from seasonal hiring to a general recovery, has been ruled out. The size of the cut is not at issue. How often hiring is measured is a detail of the data. And that January comes before June is true but is exactly the weak point rather than a hidden assumption.

Read: 'Sixty percent of respondents favored the change.' Which question would most help a reader judge this claim?

• a.What format was the report published in
• b.Who paid to print the final document
• c.Who was asked and how were they chosen✓
• d.How long did the survey take to complete

A percentage means little until you know whose opinions it summarizes and whether they represent the group in question, which is a matter of sampling. The time the survey took does not affect whom it reached. The publication format is irrelevant. And printing costs say nothing about the sample.

Read: 'Critics of the plan say it costs too much. They are wrong, because the plan is affordable.' The reply fails because it—

• a.misquotes what the critics actually said about cost
• b.concedes the critics' main point
• c.restates the disagreement without evidence✓
• d.introduces a new topic that is irrelevant here

Asserting affordability is simply denying the objection in different words, and no figure or reason is offered to settle which side is right. The reply stays on the topic the critics raised. It represents their position accurately. And it concedes nothing.

Read: 'The author concludes that the program should be expanded, and admits that the evaluation covered only one site.' The admission mainly—

• a.shows that the author is being dishonest with readers
• b.makes the evidence irrelevant
• c.proves that the conclusion the author reached is false
• d.limits how far the conclusion can be pushed✓

Stating the limits of the evidence tells the reader how much weight the conclusion can bear, which is a mark of careful argument rather than a defect. A single site does not prove the conclusion wrong. Disclosing a limitation is the opposite of dishonesty. And evidence from one site is still evidence, just narrower.

Read: 'Four schools tried the later start time. Test scores rose in three of them and fell slightly in the fourth.' A fair summary is that the results were—

• a.entirely positive across the board
• b.too mixed to show any pattern
• c.mostly positive but not uniform✓
• d.negative in the majority of schools

Three improvements and one small decline is a favorable pattern with an exception, and saying so reports what happened without overstating it. Claiming it was positive across the board erases the fourth school. Calling it patternless ignores the three. And describing a majority as negative reverses the count.

Read: 'The report is dated 2004 and describes the internet habits of teenagers.' Using it to describe teenagers today is a problem mainly because—

• a.reports are never reliable sources
• b.the author had an obvious bias
• c.the sample was certainly too small
• d.the evidence may be out of date✓

Behavior in this area has changed enormously since 2004, so the age of the study is the immediate objection, whatever its quality was at the time. Reports are perfectly capable of being reliable. Nothing is said about the sample size. And no evidence of bias is given.

Read: 'Opponents claim the fee will drive shops away. Yet every shop that closed last year cited rent, not fees.' The writer answers the objection by—

• a.questioning the motives of opponents
• b.offering evidence that points elsewhere✓
• c.conceding that shops did close
• d.changing the subject to rents in general

The reason shops actually gave is used to challenge the proposed cause, which is a reply on the merits. The writer does note that shops closed, but that is the setting for the evidence rather than a concession of the point. Rent is raised because the shops raised it, not as a new subject. And nobody's motives are questioned.

Which word correctly completes the sentence: 'The box of rusted nails ______ on the top shelf'?

• a.sit
• b.sits✓
• c.were sitting
• d.have sat

The subject is 'box,' which is singular, so the verb must be singular no matter how many nails the phrase after it mentions. 'Sit' agrees with 'nails' instead of with the real subject, which is the trap the phrase is there to set. 'Were sitting' is plural as well. And 'have sat' is likewise a plural form of the present perfect.

Which word correctly completes the sentence: 'The supervisor ______ we met on Tuesday approved the order'?

• a.whom✓
• b.whose
• c.which
• d.who

The pronoun is the object of 'met' — we met him — and the objective form is 'whom.' 'Who' is the subject form and would be right only if the pronoun did the meeting. 'Which' is used for things rather than people. And 'whose' shows possession, which nothing here requires.

Which word correctly completes the sentence: 'Of the three routes, the coastal one is the ______'?

• a.more longer
• b.most long
• c.longer
• d.longest✓

With three or more items the superlative is required, and for a short adjective that means the -est ending. 'Longer' is the comparative and is used when exactly two things are compared. 'Most long' forms the superlative the wrong way for a one-syllable adjective. And 'more longer' doubles the comparative, which is never correct.

Which sentence uses a colon correctly?

• a.The kit contains: a wrench, pliers, and a driver.
• b.The kit contains three tools, a wrench: pliers and a driver.
• c.The kit: contains three tools, a wrench, pliers, and a driver.
• d.The kit contains three tools: a wrench, pliers, and a driver.✓

A colon introducing a list must follow a complete sentence, and 'The kit contains three tools' can stand alone. Putting the colon straight after 'contains' breaks the sentence in the middle of a verb and its object. Dropping a colon inside the list itself separates nothing meaningful. And a colon after the subject cuts the sentence off from its own verb.

Which word correctly completes the sentence: 'The new safety rule will ______ every department in the plant'?

• a.affect✓
• b.effect
• c.effected
• d.affects

The verb meaning to have an influence on something is 'affect'; 'effect' as a noun is the result. 'Affects' is the wrong form after 'will,' which needs the bare infinitive. And 'effected' would mean brought about, which a rule cannot do to a department, besides being the wrong tense here.

Which word correctly completes the sentence: 'The second applicant had more experience ______ the first'?

• a.as
• b.from
• c.then
• d.than✓

'Than' is the word used in comparisons, and 'more experience' demands it. 'Then' refers to time or sequence and is a different word entirely, however similar it sounds. 'From' is used with 'different,' not with 'more.' And 'as' would need the form 'as much experience as.'

Which sentence shows the correct plural possessive?

• a.The employees lounge was repainted last week.
• b.The employees' lounge was repainted last week.✓
• c.The employees's lounge was repainted last week.
• d.The employee's lounge was repainted last week.

A lounge belonging to more than one employee takes the plural 'employees' with the apostrophe after the s. Placing the apostrophe before the s makes the lounge belong to one employee. Leaving the apostrophe out removes the possession altogether. And adding a second s after the apostrophe is not the form used for a regular plural.

Which word keeps the verb tenses consistent: 'He walked to the counter and ______ for a receipt'?

• a.will ask
• b.asked✓
• c.asks
• d.is asking

'Walked' sets the sentence in the past, so the second verb in the pair must be past as well. 'Asks' shifts to the present in the middle of one action. 'Is asking' shifts to the present progressive. And 'will ask' jumps to the future, which leaves the two halves describing different times.

Which sentence punctuates the quotation correctly?

• a.'We close at nine' the clerk said.
• b.'We close at nine.' the clerk said.
• c.'We close at nine', the clerk said.
• d.'We close at nine,' the clerk said.✓

When a quotation is followed by words such as 'the clerk said,' the comma goes inside the closing quotation mark. Placing the comma outside is the British convention and is marked wrong on American tests. A period ends the sentence and cannot be followed by 'the clerk said.' And omitting the punctuation entirely runs the quotation into the attribution.

Which revision corrects the dangling modifier in 'After finishing the inspection, the report was filed'?

• a.The report, after finishing the inspection, was filed.
• b.After the inspection was finishing, the report was filed.
• c.After finishing the inspection, the report was filed promptly.
• d.After finishing the inspection, the engineer filed the report.✓

The opening phrase needs a subject that could have done the finishing, and naming the engineer supplies one. Adding 'promptly' leaves the report as the thing that finished the inspection. Moving the phrase into the middle of the sentence changes nothing about who finished. And 'was finishing' creates a new error without fixing the old one.

Which sentence hyphenates the compound modifier correctly?

• a.She interviewed a well-known author last spring.✓
• b.The author she interviewed is well-known.
• c.She interviewed a well known author last spring.
• d.She interviewed a well-known-author last spring.

A two-word modifier placed before the noun it describes takes a hyphen, so 'well-known author' is correct. Leaving the hyphen out before the noun loses the link between the two words. Hyphenating the noun into the modifier joins words that are not a unit. And after the verb, as in 'is well known,' the hyphen is normally dropped.

Which sentence uses the correct pronoun form?

• a.The dispute was settled between yourself and I.
• b.The dispute was settled between you and myself.
• c.The dispute was settled between you and me.✓
• d.The dispute was settled between you and I.

'Between' is a preposition, so the pronouns after it take the objective form, which is 'me.' 'I' is the subject form and sounds formal here without being correct. 'Yourself' and 'myself' are reflexive forms, used when the subject and object are the same person, which is not the case in this sentence.

Which word correctly completes the sentence: 'If I ______ more time, I would rewrite the whole section'?

• a.will have
• b.would have
• c.have
• d.had✓

A condition contrary to present fact pairs the past form in the if-clause with 'would' in the main clause, so 'had' is the form required. 'Have' states a real present condition and does not match 'would rewrite.' 'Will have' puts a future in a clause that cannot take one. And 'would have' repeats the modal that already appears in the second half.

What is 3/8 + 1/4?

• a.4/12
• b.3/4
• c.5/8✓
• d.1/2

Rewrite 1/4 as 2/8 so the denominators match, then add the numerators: 3/8 + 2/8 = 5/8. Adding numerators and denominators straight across gives 4/12, which is what makes fractions look harder than they are. One half is 4/8 and falls just short. And 3/4 is 6/8, one eighth too much.

What is 2/3 × 3/5?

• a.5/8
• b.2/5✓
• c.6/5
• d.1/5

Multiply straight across to get 6/15, then divide both parts by 3 for 2/5. Adding across instead of multiplying produces 5/8. Inverting the second fraction gives 6/5, which is what division would call for. And 1/5 drops a factor somewhere in the reduction.

What is 5/6 ÷ 1/3?

• a.2 1/2✓
• b.5/18
• c.2/9
• d.1 1/2

Dividing by a fraction means multiplying by its reciprocal: 5/6 × 3/1 = 15/6, which reduces to 5/2, or 2 1/2. Multiplying by 1/3 instead of dividing gives 5/18. The answer 1 1/2 would come from a different dividend altogether. And 2/9 does not arise from any correct step here.

Write 0.45 as a fraction in lowest terms.

• a.45/10
• b.4/5
• c.1/45
• d.9/20✓

The digits end in the hundredths place, so 0.45 is 45/100, and dividing both parts by 5 gives 9/20. Writing 45/10 misplaces the decimal by a factor of ten. Four fifths is 0.8, nearly twice as large. And 1/45 inverts the number entirely.

Which list puts 5/8, 0.6 and 58% in order from least to greatest?

• a.58%, 5/8, 0.6
• b.5/8, 0.6, 58%
• c.0.6, 58%, 5/8
• d.58%, 0.6, 5/8✓

Convert everything to decimals: 58% is 0.58, 0.6 stays as it is, and 5/8 is 0.625, so the order runs 0.58, 0.60, 0.625. Reversing that order puts the largest first. Placing 0.6 below 58% mistakes 0.6 for 0.06. And putting 5/8 before 0.6 treats eight parts as smaller than they are.

What is −7 − (−3)?

• a.4
• b.−10
• c.−4✓
• d.10

Subtracting a negative is the same as adding its opposite, so −7 − (−3) becomes −7 + 3, which is −4. Treating the two minus signs as one gives −10. Changing the sign of the first number as well gives 10. And 4 has the right size but the wrong sign, since the result stays below zero.

What is the product of −3 and −5?

• a.8
• b.15✓
• c.−15
• d.−8

Two negative factors give a positive product, so (−3)(−5) = 15. Keeping the answer negative ignores that rule. The value −8 comes from adding rather than multiplying. And 8 is that same sum with the sign dropped.

Evaluate |−9| − |4|.

• a.13
• b.5✓
• c.−13
• d.−5

Absolute value strips the sign, so this is 9 − 4, which equals 5. Adding the two values after stripping the signs gives 13. Keeping the first number negative and then subtracting gives −13. And −5 reverses the order of the subtraction.

A 12-ounce bottle of juice costs $3.60. What is the price per ounce?

• a.$0.30✓
• b.$3.33
• c.$0.33
• d.$4.32

A unit rate divides cost by quantity: $3.60 ÷ 12 = $0.30 per ounce. Dividing the ounces by the dollars gives 3.33 and answers a question nobody asked. The figure $0.33 comes from dividing by 11 or from a slip in the decimal. And multiplying rather than dividing gives $4.32.

A price rises from $40 to $50. What is the percent increase?

• a.25%✓
• b.20%
• c.125%
• d.10%

Percent change divides the increase by the original amount: 10 ÷ 40 = 0.25, or 25%. Dividing by the new price instead gives 20%, which is the classic trap in these problems. The raw increase of 10 dollars is not itself 10 percent. And 125% is the new price as a share of the old, not the increase.

8 is what percent of 32?

• a.4%
• b.40%
• c.400%
• d.25%✓

Divide the part by the whole and convert: 8 ÷ 32 = 0.25, which is 25%. The value 4 is the result of dividing 32 by 8, the reverse comparison. Forty percent of 32 would be 12.8. And 400% would make 8 four times the whole rather than a quarter of it.

An item costs $24 and sales tax is 7%. What is the total?

• a.$24.07
• b.$25.68✓
• c.$1.68
• d.$31.00

The tax is 0.07 × $24 = $1.68, and adding it to the price gives $25.68; multiplying $24 by 1.07 does both steps at once. Adding seven cents treats the percent as a flat amount. Adding seven dollars treats it as dollars rather than percent. And $1.68 is the tax alone, not the total.

A meal costs $45 and the diner leaves an 18% tip. How much is the tip?

• a.$81.00
• b.$0.81
• c.$5.31
• d.$8.10✓

Eighteen percent of $45 is 0.18 × 45 = $8.10. Moving the decimal one place too far left gives $0.81. Moving it the other way gives $81, which is more than the meal. And $5.31 would be about 11.8 percent, a rate the question did not give.

How much simple interest does $500 earn at 4% per year for 3 years?

• a.$60✓
• b.$600
• c.$20
• d.$540

Simple interest is principal times rate times time: 500 × 0.04 × 3 = $60. Leaving out the three years gives $20, the first year only. The figure $600 misplaces a decimal. And $540 is the balance after interest rather than the interest itself, and even then only if the interest were $40.

Write 3.2 × 10⁴ in standard form.

• a.320,000
• b.3,200
• c.32,000✓
• d.12.8

An exponent of 4 moves the decimal point four places to the right, turning 3.2 into 32,000. Moving it three places gives 3,200. Moving it five gives 320,000. And 12.8 is 3.2 multiplied by 4 rather than by ten to the fourth.

What is the value of (2³)²?

• a.512
• b.12
• c.32
• d.64✓

Work from the inside out: 2³ is 8, and 8² is 64; multiplying the exponents to get 2⁶ gives the same result. Multiplying the base by the exponents gives 12. Adding the exponents gives 2⁵, or 32. And 512 is 2⁹, which would come from raising 8 to the third power.

Between which two whole numbers does the square root of 50 fall?

• a.24 and 26
• b.8 and 9
• c.6 and 7
• d.7 and 8✓

Seven squared is 49 and eight squared is 64, so the square root of 50 sits just above 7. Six squared is only 36, too small to bracket 50 from above. Eight and nine bracket numbers from 64 upward. And 24 to 26 comes from halving 50 rather than taking a root.

A box measures 4 cm by 3 cm by 5 cm. What is its volume?

• a.12 cm³
• b.94 cm³
• c.60 cm³✓
• d.24 cm³

Volume of a rectangular solid is length times width times height: 4 × 3 × 5 = 60 cubic centimeters. Multiplying only two of the three dimensions gives 12. Adding the dimensions and doubling gives 24. And 94 is the surface area of this box, a different measurement in square units.

A cylinder has a radius of 3 cm and a height of 10 cm. What is its volume? (Use π ≈ 3.14.)

• a.188.4 cm³
• b.30 cm³
• c.94.2 cm³
• d.282.6 cm³✓

Volume of a cylinder is the base area times the height: 3.14 × 3² × 10 = 3.14 × 9 × 10 = 282.6 cubic centimeters. Using the circumference instead of the area gives 188.4. Squaring nothing at all and multiplying 3.14 by 3 by 10 gives 94.2. And 30 is simply radius times height, with π forgotten.

What is the total surface area of a cube with edges 4 cm long?

• a.96 cm²✓
• b.24 cm²
• c.64 cm²
• d.16 cm²

A cube has six identical square faces, each 4 × 4 = 16 square centimeters, so the surface area is 6 × 16 = 96. The value 64 is the cube's volume. One face alone is 16. And 24 is the total edge length rather than an area.

What is the area of a circle with a radius of 5 cm? (Use π ≈ 3.14.)

• a.157 cm²
• b.15.7 cm²
• c.78.5 cm²✓
• d.31.4 cm²

Area is π times the radius squared: 3.14 × 25 = 78.5 square centimeters. The value 31.4 is the circumference, which uses 2πr instead. Half of that circumference is 15.7. And 157 doubles the correct area, as if the diameter had been squared in place of the radius.

A right triangle has legs of 6 cm and 8 cm. How long is the hypotenuse?

• a.7 cm
• b.14 cm
• c.48 cm
• d.10 cm✓

By the Pythagorean theorem, 6² + 8² = 36 + 64 = 100, and the square root of 100 is 10. Adding the legs gives 14, which is longer than any side of this triangle can be. Multiplying them gives 48, which is twice the area. And 7 is the average of the legs, not a side length.

A rectangle is 15 m long and 8 m wide. What is its perimeter?

• a.120 m
• b.46 m✓
• c.60 m
• d.23 m

Perimeter adds all four sides: 2(15 + 8) = 46 meters. The product 120 is the area, measured in square meters rather than meters. Adding the length and width once gives 23, which is only half the way around. And 60 would be the perimeter of a 15-by-15 square.

How many inches are in 2.5 feet?

• a.24
• b.36
• c.25
• d.30✓

There are 12 inches in a foot, so 2.5 × 12 = 30 inches. The value 25 comes from treating the conversion as a decimal shift. Twenty-four inches is exactly two feet and leaves out the half. And 36 inches is three feet, half a foot too many.

A container holds 2,500 milliliters. How many liters is that?

• a.2.5✓
• b.25
• c.0.25
• d.250

A liter is 1,000 milliliters, so dividing 2,500 by 1,000 gives 2.5 liters. Dividing by 100 gives 25. Dividing by 10 gives 250. And 0.25 divides by 10,000, one decimal place too far.

A parallelogram has a base of 12 cm and a height of 7 cm. What is its area?

• a.38 cm²
• b.84 cm²✓
• c.42 cm²
• d.19 cm²

Area of a parallelogram is base times height: 12 × 7 = 84 square centimeters, with no factor of one half. Halving the product gives 42, which is the area of a triangle with the same base and height. Adding and doubling gives 38. And 19 is just the base plus the height.

A rectangular patio measures 10 ft by 6 ft. A 3 ft by 4 ft rectangular planter is cut out of it. What area of patio remains?

• a.60 square feet
• b.48 square feet✓
• c.72 square feet
• d.12 square feet

The whole rectangle is 10 × 6 = 60 square feet and the planter is 3 × 4 = 12, so 60 − 12 = 48 square feet remain. Reporting 60 forgets to remove the planter. Adding rather than subtracting gives 72. And 12 is the planter itself rather than what is left.

On a floor plan, 1 inch represents 4 feet. A wall drawn 3.5 inches long is actually—

• a.7 feet
• b.12 feet
• c.1.14 feet
• d.14 feet✓

Each inch stands for 4 feet, so 3.5 × 4 = 14 feet. Doubling instead of quadrupling gives 7. Ignoring the half inch gives 12. And dividing the drawing length by the scale gives 1.14, which inverts the relationship.

A trapezoid has parallel sides of 8 cm and 12 cm and a height of 5 cm. What is its area?

• a.50 cm²✓
• b.60 cm²
• c.25 cm²
• d.100 cm²

Average the parallel sides and multiply by the height: (8 + 12) ÷ 2 = 10, and 10 × 5 = 50 square centimeters. Forgetting to average gives 100. Halving twice gives 25. And 60 multiplies 12 by 5 while ignoring the shorter side.

A circular tabletop has a diameter of 14 inches. What is its circumference? (Use π ≈ 22/7.)

• a.44 inches✓
• b.22 inches
• c.154 inches
• d.88 inches

Circumference equals π times the diameter: 22/7 × 14 = 44 inches. Using the radius in place of the diameter gives 22. Doubling the diameter before multiplying gives 88. And 154 is the area in square inches, which uses the radius squared.

A wheelchair ramp rises 2 feet over a horizontal run of 24 feet. What is its slope?

• a.1/24
• b.1/12✓
• c.1/2
• d.12

Slope is rise over run: 2 ÷ 24 = 1/12. Dividing the run by the rise gives 12, which inverts the ratio and describes an impossibly steep ramp. One half ignores the run almost entirely. And 1/24 uses a rise of one foot rather than the two feet the ramp actually climbs.

Solve for x: 4x − 9 = 2x + 7.

• a.4
• b.16
• c.−1
• d.8✓

Subtract 2x from both sides to get 2x − 9 = 7, add 9 to get 2x = 16, then divide by 2 for x = 8. Forgetting to divide leaves 16. Subtracting 9 from 7 instead of adding gives −1. And 4 solves a different equation entirely; substituting it gives 7 on the left and 15 on the right.

Solve for x: 3(x + 2) = 21.

• a.5✓
• b.7
• c.19
• d.9

Divide both sides by 3 to get x + 2 = 7, then subtract 2 for x = 5. Stopping after the division leaves 7. Subtracting 2 from 21 without dividing gives 19. And 9 comes from dividing 21 by 3 and then adding 2 rather than subtracting.

Solve for x: x/3 + 4 = 10.

• a.42
• b.18✓
• c.2
• d.6

Subtract 4 from both sides to get x/3 = 6, then multiply by 3 for x = 18. Dividing instead of multiplying gives 2. Adding 4 before multiplying gives 42. And 6 is the value of x/3, not of x.

Solve for y: 2y − 5 = 13.

• a.9✓
• b.6.5
• c.18
• d.4

Add 5 to both sides to get 2y = 18, then divide by 2 for y = 9. Subtracting 5 instead of adding gives 2y = 8 and y = 4. Forgetting the division leaves 18. And 6.5 divides 13 by 2 without dealing with the 5 at all.

Simplify: 3x + 5 − x + 2.

• a.2x + 7✓
• b.4x + 7
• c.2x + 3
• d.9x

Combine the x terms, 3x − x = 2x, and the constants, 5 + 2 = 7, giving 2x + 7. Adding the x terms instead of subtracting gives 4x + 7. Subtracting the constants gives 2x + 3. And 9x lumps unlike terms together, which is the error the whole exercise guards against.

Multiply: (x + 3)(x + 4).

• a.2x + 7
• b.x² + 7x + 12✓
• c.x² + 12x + 7
• d.x² + 12

Multiply every term by every term: x·x gives x², the outer and inner products give 4x and 3x for 7x, and 3·4 gives 12. Swapping the middle and last terms gives x² + 12x + 7. Multiplying only the first and last terms gives x² + 12. And 2x + 7 is what you get by adding the two binomials instead of multiplying.

Factor completely: x² − 9.

• a.(x − 3)(x − 3)
• b.(x + 9)(x − 1)
• c.(x + 3)(x − 3)✓
• d.x(x − 9)

A difference of two squares factors into a sum times a difference, and here the square roots are x and 3. Using two identical factors would give x² − 6x + 9, which has a middle term this expression does not. The pair 9 and −1 multiplies to −9 but leaves a middle term of 8x. And factoring out an x is impossible when the second term has no x in it.

Factor: x² + 5x + 6.

• a.(x − 2)(x − 3)
• b.(x + 5)(x + 1)
• c.(x + 1)(x + 6)
• d.(x + 2)(x + 3)✓

Look for two numbers that multiply to 6 and add to 5, which are 2 and 3. The pair 1 and 6 multiplies to 6 but adds to 7. Two negatives would multiply to 6 but add to −5, giving the wrong middle sign. And 5 and 1 add to 6 and multiply to 5, exactly reversing what is needed.

If x² = 49, what are the possible values of x?

• a.24.5 only
• b.7 and −7✓
• c.7 only
• d.−7 only

Both 7 and −7 square to 49, so a quadratic of this form has two solutions. Reporting only the positive root is the most common omission on this kind of problem. Halving 49 gives 24.5, which is not a square root at all. And the negative root alone is just as incomplete as the positive one.

Solve the inequality: −3x > 12.

• a.x > −4
• b.x > 4
• c.x < −4✓
• d.x < 4

Dividing both sides by a negative number reverses the direction of the inequality, so −3x > 12 becomes x < −4. Keeping the sign as it was gives x > −4, the single most common error here. Dropping the negative from the answer gives x < 4. And x > 4 gets both the sign and the direction wrong.

Solve the system: x + y = 10 and x − y = 4.

• a.x = 6, y = 4
• b.x = 7, y = 3✓
• c.x = 3, y = 7
• d.x = 14, y = 4

Adding the two equations eliminates y and gives 2x = 14, so x = 7 and then y = 3. Swapping the values gives x = 3 and y = 7, which satisfies the first equation but makes the second −4. The pair 6 and 4 sums to 10 but differs by 2. And 14 and 4 satisfies neither equation.

Four times a number, decreased by 6, is 18. What is the number?

• a.48
• b.4.5
• c.6✓
• d.3

Write 4n − 6 = 18, add 6 to get 4n = 24, then divide by 4 for n = 6. Subtracting 6 instead of adding gives 4n = 12 and n = 3. Multiplying 18 by 4 and adding gives 48. And 4.5 divides 18 by 4 and never handles the 6.

Which expression means 'five less than twice a number n'?

• a.5n − 2
• b.2(n − 5)
• c.5 − 2n
• d.2n − 5✓

Twice the number is 2n, and five less than that subtracts 5 from it. Writing 5 − 2n reverses the subtraction, which changes the value at every n but zero. The form 2(n − 5) subtracts first and doubles afterward, giving 2n − 10. And 5n − 2 swaps the roles of the two numbers.

Evaluate 2a² − b when a = 3 and b = 5.

• a.1
• b.18
• c.13✓
• d.31

Square first: a² is 9, so 2 × 9 = 18, and 18 − 5 = 13. Squaring the product 2a instead of a alone gives 36 − 5 = 31. Stopping before subtracting b leaves 18. And treating a² as a gives 6 − 5 = 1.

Solve the proportion: 3/4 = x/20.

• a.12
• b.26.7
• c.15✓
• d.5

Cross multiply to get 4x = 60, then divide by 4 for x = 15. Multiplying 3 by 4 gives 12 and ignores the 20 entirely. Dividing 80 by 3 gives about 26.7, which crosses the wrong pair. And 5 comes from dividing 20 by 4 without using the 3.

The area of a rectangle is A = lw. Solved for w, this becomes—

• a.w = Al
• b.w = l/A
• c.w = A/l✓
• d.w = A − l

To isolate w, divide both sides by l, which leaves w = A divided by l. Multiplying instead of dividing gives Al, which has the units of a volume. Writing l/A inverts the fraction. And subtracting l treats a product as a sum.

Solve for x: 0.5x = 7.

• a.7.5
• b.14✓
• c.3.5
• d.0.07

Dividing by 0.5 is the same as multiplying by 2, so x = 14. Multiplying by 0.5 instead gives 3.5, which is half the target rather than double. Adding 0.5 gives 7.5. And 0.07 misplaces the decimal by two places.

A rectangle has perimeter P = 2l + 2w. If P = 30 and l = 9, what is w?

• a.6✓
• b.12
• c.21
• d.3

Substitute to get 30 = 18 + 2w, so 2w = 12 and w = 6. Forgetting the final division leaves 12. Subtracting only one length gives 21. And 3 halves 12 twice.

Simplify: 7x + 3(x − 2).

• a.10x + 6
• b.10x − 2
• c.10x − 6✓
• d.7x + 3x − 2

Distribute the 3 across both terms to get 7x + 3x − 6, then combine like terms for 10x − 6. Distributing to the x only and keeping +6 gets the sign wrong. Leaving −2 undistributed drops the multiplication. And the last choice is an incomplete step rather than a simplified expression.

Solve for x: 5 − 2x = 11.

• a.8
• b.−3✓
• c.−8
• d.3

Subtract 5 from both sides to get −2x = 6, then divide by −2 for x = −3. Dropping the negative gives 3, which substituted back yields −1 rather than 11. Adding 5 to 11 and halving gives 8. And −8 keeps that same error and adds a sign.

In the equation y = 3x − 2, the y-intercept is—

• a.−2✓
• b.−3
• c.3
• d.2

In slope-intercept form the constant term is the value of y when x is zero, so the line crosses the y-axis at −2. The 3 is the slope, which describes steepness rather than a crossing point. Positive 2 has the right size and the wrong sign. And −3 confuses the slope with the intercept and flips its sign.

What is the slope of the line y = −(1/2)x + 4?

• a.−1/2✓
• b.−4
• c.4
• d.1/2

The coefficient of x is the slope, and here it is negative one half, meaning the line falls as it moves right. Dropping the negative gives a line that rises instead. The 4 is the y-intercept. And −4 is that intercept with the sign changed.

Which point lies on the line y = 2x + 1?

• a.(1, 4)
• b.(3, 5)
• c.(3, 7)✓
• d.(2, 3)

Substituting x = 3 gives y = 2(3) + 1 = 7, so the point (3, 7) satisfies the equation. The point (3, 5) would need the equation y = 2x − 1. Substituting x = 1 gives 3, not 4. And x = 2 gives 5, not 3.

A table shows that x = 1 gives y = 5, x = 2 gives y = 8, and x = 3 gives y = 11. Which rule fits?

• a.y = x + 4
• b.y = 5x
• c.y = 3x + 2✓
• d.y = 2x + 3

Each step of 1 in x raises y by 3, so the slope is 3, and working back from x = 1 gives an intercept of 2. The rule y = 5x fits the first row only and fails the second. The rule y = x + 4 rises too slowly. And y = 2x + 3 fits the first row and then falls behind.

What is the slope of the line through (−2, 3) and (2, 11)?

• a.2✓
• b.−2
• c.4
• d.1/2

Slope is the change in y over the change in x: (11 − 3) ÷ (2 − (−2)) = 8 ÷ 4 = 2. Inverting the fraction gives 1/2. Mishandling the negative x-value gives −2. And 4 comes from dividing by 2 instead of by 4.

What is the slope of a horizontal line?

• a.1
• b.−1
• c.0✓
• d.undefined

A horizontal line has no rise over any run, so the slope is zero. A slope of 1 describes a line rising at forty-five degrees. Undefined is the slope of a vertical line, where the run is zero and division is impossible. And −1 describes a line falling at forty-five degrees.

Which set of ordered pairs represents a function?

• a.(1, 2), (1, 5), (3, 6)
• b.(1, 2), (2, 4), (3, 6)✓
• c.(2, 3), (2, 3), (2, 7)
• d.(4, 1), (4, 2), (4, 3)

A function assigns exactly one output to each input, so the set in which every x-value appears once and only once is the function. A set pairing x = 1 with both 2 and 5 gives one input two outputs and fails. A set in which x = 4 appears three times with different partners fails for the same reason. And repeating x = 2 with conflicting y-values is that same failure once more, whatever else the set contains.

If f(x) = 2x + 5, what is f(4)?

• a.13✓
• b.11
• c.14
• d.9

Substitute 4 for x: 2(4) + 5 = 8 + 5 = 13. Adding 4 and 5 gives 9 and skips the multiplication. Using 2 + 4 + 5 gives 11. And 14 would require the rule 2x + 6.

A line on a graph falls steadily from left to right. Its slope is—

• a.positive
• b.negative✓
• c.zero
• d.undefined

Falling to the right means y decreases as x increases, which makes the ratio of rise to run negative. A positive slope rises to the right. A zero slope is flat. And an undefined slope belongs to a vertical line, which neither rises nor falls across the page.

On a graph of distance against time, a flat horizontal segment means the object is—

• a.moving at a steady speed
• b.moving backward
• c.speeding up
• d.not moving✓

If distance does not change while time passes, the object has stopped. Speeding up would show as a curve growing steeper. Steady speed would show as a straight line sloping upward. And moving back toward the start would show as a line sloping down.

Where does the line y = 4x − 8 cross the x-axis?

• a.(0, 2)
• b.(−2, 0)
• c.(2, 0)✓
• d.(0, −8)

The x-axis is where y = 0, so 4x − 8 = 0 gives x = 2 and the point (2, 0). Writing (0, 2) puts the value on the wrong axis. The point (0, −8) is the y-intercept, the crossing on the other axis. And (−2, 0) has the sign of x reversed.

A line is parallel to y = 5x + 1. Its slope must be—

• a.5✓
• b.1
• c.−1/5
• d.−5

Parallel lines never meet, which requires identical slopes, so the slope is 5. The 1 is the intercept of the given line, not its slope. The value −5 describes a line falling as steeply as this one rises. And −1/5 is the slope of a line perpendicular to it.

Which equation describes a line with slope 3 that passes through (0, −4)?

• a.y = −4x + 3
• b.y = 4x − 3
• c.y = 3x + 4
• d.y = 3x − 4✓

Because the point given has x = 0, it is the y-intercept, so the equation is y = 3x − 4. Writing +4 puts the crossing above the origin instead of below. The equation y = −4x + 3 swaps the slope and the intercept. And y = 4x − 3 swaps them and changes the signs.

A scatterplot shows points rising from lower left to upper right. The two variables show—

• a.no association at all
• b.a negative association
• c.a perfect causal link
• d.a positive association✓

Points that rise together mean that as one variable increases so does the other, which is a positive association. A negative association would show points falling to the right. No association would show a shapeless cloud. And no scatterplot by itself establishes that one variable causes the other.

A repair shop charges $25 plus $5 for each hour of labor, so the cost is C = 25 + 5h. In this model the 5 represents—

• a.the total cost of a short job
• b.the fixed charge for any visit
• c.the cost of each additional hour✓
• d.the number of hours worked

The 5 multiplies the hours, so it is the rate at which cost grows with each hour, the slope of the line. The fixed charge that applies before any labor is the 25. A short job costs 25 plus whatever labor it takes, which is not 5 by itself. And the number of hours is h, the variable the 5 is multiplied by.

The graph of the equation y = x² is—

• a.a pair of parallel lines
• b.a U-shaped curve✓
• c.a straight line
• d.a circle

Squaring makes negative and positive x-values give the same positive y, so the graph is a parabola opening upward, symmetric about the y-axis. A straight line comes from an equation where x appears to the first power only. A circle requires both variables squared and summed. And parallel lines come from a pair of separate linear equations.

Which cell structure releases the energy stored in food molecules?

• a.The cell membrane
• b.The vacuole
• c.The mitochondrion✓
• d.The ribosome

Mitochondria carry out cellular respiration, breaking down sugars in the presence of oxygen and capturing the released energy in a form the cell can spend. The cell membrane controls what crosses into and out of the cell. A vacuole is a storage compartment, largest in plant cells. And ribosomes assemble proteins, a job that consumes energy rather than supplying it.

The instructions a cell uses to build its proteins are carried by—

• a.glucose
• b.DNA✓
• c.cholesterol
• d.hemoglobin

DNA stores the sequence information that specifies each protein, which is why it is copied before a cell divides and passed to both daughter cells. Glucose is a fuel molecule and carries no information. Hemoglobin is itself a protein, one of the products rather than the instructions. And cholesterol is a lipid that helps form membranes.

How do the cells produced by meiosis differ from those produced by mitosis?

• a.They contain no genetic material at all
• b.They carry twice the number of chromosomes
• c.They are unable to divide ever again
• d.They carry half the number of chromosomes✓

Meiosis halves the chromosome number to make sex cells, so that fertilization restores the full set rather than doubling it each generation. Doubling is exactly what meiosis prevents. The cells are not dead ends, since a fertilized egg divides many times. And they certainly contain genetic material; half a set is still a set.

An allele is described as dominant when it—

• a.shows in the trait even with one copy present✓
• b.appears only when two copies are present
• c.is found more often in a population
• d.changes into a different allele over time

A dominant allele expresses itself in the observable trait whenever it is present, so a single copy is enough to mask a recessive partner. Needing two copies is the definition of recessive, which is the contrast being drawn. Dominance says nothing about how common an allele is; rare alleles can be dominant. And alleles do not convert into one another, though mutation can create new ones.

Two parents are each heterozygous for a trait, carrying one dominant and one recessive allele. What fraction of their offspring is expected to show the recessive trait?

• a.One in four✓
• b.One in two
• c.None at all
• d.Three in four

A Punnett square for this cross gives one homozygous dominant, two heterozygous and one homozygous recessive, so a quarter of the offspring are expected to show the recessive form. One in two would be the result of crossing a heterozygote with a homozygous recessive parent. Three in four is the fraction expected to show the dominant trait. And a recessive trait can certainly appear, since both parents carry the allele without showing it.

The difference between an organism's genotype and its phenotype is that the phenotype is—

• a.the trait that can actually be observed✓
• b.the number of chromosomes in its cells
• c.the species to which it belongs
• d.the set of alleles it happens to carry

Phenotype names what shows: the height, the color, the enzyme activity you can measure. The alleles themselves are the genotype, the underlying combination that the phenotype partly reflects. Chromosome number is a feature of the karyotype rather than either term. And species membership is a classification, not an individual's expressed trait.

Natural selection acts on a population when—

• a.the environment stays exactly the same across generations
• b.organisms decide which traits to pass on
• c.every individual remakes itself to suit the habitat it lives in
• d.individuals with certain traits leave more offspring✓

Selection works through differential reproduction: heritable traits that help their bearers survive and breed become more common in later generations. Individuals do not remake themselves to fit their surroundings; the variation is already present and is sorted. A wholly unchanging environment gives selection less to act on rather than more. And no organism chooses what it transmits.

The similar bone arrangement in a human arm, a whale flipper and a bat wing is evidence that these animals—

• a.use their limbs for the same task
• b.share a common ancestor✓
• c.belong to the same living species
• d.live in the same kind of habitat

The same underlying skeletal plan put to very different uses is what biologists call a homologous structure, and shared ancestry is the explanation for the shared plan. The three animals live in quite different habitats, which is part of the point. Their limbs do entirely different jobs, so function cannot explain the resemblance. And they are unmistakably separate species.

A bacterial population survives repeated treatment with the same antibiotic and becomes harder to kill. This is best explained as—

• a.the antibiotic itself growing weaker with repeated use
• b.selection of resistant individuals already present✓
• c.bacteria gradually learning how to avoid the medicine
• d.patients becoming immune to the drug

Chance variation means a few bacteria can survive the drug, and when the rest are killed those few multiply, so resistance spreads through the population. Bacteria have no capacity to learn anything. The chemical itself does not weaken; the population changes. And it is the bacteria, not the patient, that become resistant, which is why the distinction matters clinically.

The role of an enzyme in a cell is to—

• a.carry oxygen in the blood
• b.speed up a chemical reaction✓
• c.store genetic information
• d.form the wall of the cell

Enzymes are catalysts: they lower the energy needed for a specific reaction so it proceeds fast enough to sustain life, and they emerge unchanged to do it again. Genetic information is stored in DNA. Oxygen transport is the work of hemoglobin. And cell walls are built from carbohydrates such as cellulose in plants.

Sweating when body temperature rises is an example of—

• a.metabolism
• b.photosynthesis
• c.homeostasis✓
• d.reproduction

Homeostasis is the maintenance of steady internal conditions, and evaporating water off the skin is one of the body's ways of pushing temperature back toward its set point. Metabolism is the sum of chemical reactions in the body, which generates the heat rather than regulating it. Reproduction produces new organisms. And photosynthesis occurs in plants and some microbes, not in people.

In the human lungs, oxygen passes into the blood across the walls of—

• a.the diaphragm
• b.the alveoli✓
• c.the trachea
• d.the bronchi

The alveoli are the tiny sacs at the ends of the airways, thin-walled and richly supplied with capillaries, and gas exchange happens there. The trachea and the bronchi are conducting tubes that carry air toward them without exchanging much of anything. And the diaphragm is the muscle whose contraction draws air in.

Most absorption of nutrients from digested food takes place in—

• a.the large intestine
• b.the esophagus
• c.the small intestine✓
• d.the stomach

The small intestine is lined with folds and tiny projections that give it an enormous surface area, and it is where the products of digestion cross into the blood. The stomach mainly stores food and begins protein digestion with acid and enzymes. The esophagus only transports food downward. And the large intestine chiefly reclaims water and salts from what is left.

Signals travel through the human nervous system along—

• a.tendons
• b.alveoli
• c.neurons✓
• d.platelets

A neuron is the cell built for the job, receiving a signal at one end and passing it along its fiber to the next cell. Tendons are connective tissue joining muscle to bone. Platelets are blood cell fragments involved in clotting. And alveoli are air sacs in the lungs.

A vaccine protects against a disease by—

• a.prompting the immune system to prepare defenses✓
• b.blocking the germ from entering the body
• c.killing the germ once the first symptoms have appeared
• d.replacing the gene that causes the illness in a patient

A vaccine presents the immune system with a harmless version or piece of a pathogen so that antibodies and memory cells are ready before a real exposure. Killing germs after symptoms begin is what a treatment such as an antibiotic attempts. Gene replacement is gene therapy, a different technology for different diseases. And a vaccine does not form a barrier; the germ can still enter and is then met by a prepared defense.

Why are antibiotics ineffective against a viral illness such as influenza?

• a.Antibiotics act on features that viruses lack✓
• b.Antibiotics only work on animal cells
• c.Viruses are too small for any medicine
• d.Viruses reproduce faster than any drug acts

Antibiotics attack structures and processes specific to bacteria, such as the bacterial cell wall or bacterial ribosomes, and a virus has neither, which is why the drug has nothing to act on. Size is not the obstacle; antiviral medicines do exist. Antibiotics are not aimed at animal cells at all, which is what makes them safe to take. And speed of reproduction is not the reason the drug fails.

In photosynthesis, a plant uses carbon dioxide, water and light energy to produce—

• a.sugar and oxygen✓
• b.starch and hydrogen
• c.protein and nitrogen
• d.carbon dioxide and water

Photosynthesis builds a sugar from carbon dioxide and water and releases oxygen as a by-product, which is the source of nearly all the oxygen in the air. Protein synthesis requires nitrogen taken up separately as nitrate and is a different process. Plants do store starch, but it is made later from sugar, and hydrogen gas is not released. And carbon dioxide and water are the inputs, not the products.

Cellular respiration in human cells consumes glucose and oxygen and releases—

• a.sugar, oxygen and stored light energy
• b.nitrogen, water and heat only
• c.protein, salt and electrical charge
• d.carbon dioxide, water and usable energy✓

Respiration is the reverse direction from photosynthesis: the carbon in glucose leaves as carbon dioxide, the hydrogen ends up in water, and the energy released is captured for the cell's work with some lost as heat. Producing sugar and oxygen is what photosynthesis does. Protein and salt are not products of this reaction. And nitrogen plays no part in it.

In an energy pyramid for an ecosystem, the amount of energy available at each higher level—

• a.stays about the same
• b.doubles at every step
• c.decreases sharply✓
• d.increases sharply

Most of the energy an organism takes in is spent staying alive and lost as heat, so only a small fraction passes to whatever eats it, which is why food chains are short and top predators are few. Energy cannot increase as it moves up, since nothing is added. Staying constant would violate that same loss. And doubling is the opposite of what happens.

Decomposers such as fungi and bacteria are important to an ecosystem because they—

• a.control the size of predator groups
• b.add oxygen to the atmosphere
• c.return nutrients to the soil✓
• d.produce food from sunlight

Decomposers break down dead tissue and waste, releasing nitrogen, phosphorus and other elements in forms that plants can take up again, which is what keeps the nutrient cycle turning. Making food from sunlight is the producers' role. Predator numbers are regulated by prey supply and competition. And oxygen is added by photosynthesis, while decomposition generally consumes it.

The carrying capacity of a habitat is—

• a.the total area the habitat covers
• b.the number of different species it currently holds
• c.the rate at which its population grows each year
• d.the largest population it can support over time✓

Carrying capacity is set by the limiting resources — food, water, space, nesting sites — and a population that overshoots it falls back. The number of species present is richness, a measure of variety rather than of a ceiling. Growth rate describes how fast a population changes, not where it levels off. And area alone says nothing about how much life the ground can support.

A graph shows a rabbit population falling steeply one year. What is the most likely effect on the fox population that preys on those rabbits?

• a.It falls in the following period✓
• b.It rises immediately and then levels
• c.It is unaffected by the change
• d.It rises in the following period

Predators depend on their prey for food, so fewer rabbits means fewer foxes surviving and breeding, and the fox decline lags the rabbit decline by a season or more. A rise would require more food, not less. Being unaffected would mean the foxes had another equally good food source, which the question does not offer. And an immediate rise gets the direction and the timing both wrong.

An introduced species often spreads rapidly in its new range because—

• a.it reproduces more slowly than natives
• b.the new habitat has no resources for natives
• c.it needs fewer nutrients than any native
• d.local predators and diseases do not control it✓

A species arriving without the predators, parasites and diseases that held it in check at home can multiply faster than native competitors, which is what makes some introductions invasive. Slow reproduction would hinder the spread rather than help it. Lower nutrient needs may sometimes help but is not the general reason. And the habitat plainly does have resources, which is why natives were living there.

A bee gathers nectar from a flower and carries pollen to the next blossom. This relationship is—

• a.parasitism, because the bee harms the plant
• b.competition, because both want the same food
• c.mutualism, because both species benefit✓
• d.predation, because the bee consumes the plant

Each partner gains: the bee gets food and the plant gets its pollen delivered, which is the defining feature of mutualism. Parasitism would require the bee to live at the flower's expense, and pollination does the opposite. The two are not competing, since they are not after the same resource. And the bee does not kill or consume the plant, so this is not predation.

A food web is a better model than a single food chain because it shows—

• a.the seasonal migration of animals
• b.the exact number of each species
• c.the many feeding links in a community✓
• d.how long each organism lives

Most animals eat several things and are eaten by several others, so a web captures the branching connections that a single line cannot. Lifespan is not part of either model. Population sizes are shown in other diagrams, such as a pyramid of numbers. And migration is a behavior that neither a chain nor a web is built to display.

A person whose food supplies more energy than the body uses over a long period will most likely—

• a.lose weight through faster digestion
• b.store the excess as body fat✓
• c.convert the excess into vitamins
• d.excrete all of the excess energy

Energy that is taken in and not spent is stored, mostly as fat, which is the physical meaning of a sustained surplus. The body does not simply discard surplus energy; that is the whole reason a surplus matters. Vitamins are nutrients obtained from food and cannot be manufactured out of excess calories. And digestion does not speed up enough to make a surplus disappear.

Protein in the diet is used mainly to—

• a.carry oxygen to the lungs
• b.insulate the body against cold
• c.supply the fastest source of energy
• d.build and repair body tissue✓

Dietary protein is broken into amino acids that the body reassembles into its own proteins, from muscle fiber to enzymes, which is why needs rise during growth and healing. Oxygen is carried from the lungs by hemoglobin, not to them by protein in food. Insulation is largely the work of fat. And the quickest energy comes from carbohydrate.

Red blood cells are specialized to—

• a.produce digestive enzymes
• b.fight off invading bacteria and viruses
• c.help the blood form clots after an injury
• d.carry oxygen to the body's tissues✓

A red blood cell is packed with hemoglobin, which binds oxygen in the lungs and releases it where oxygen is scarce, and it even gives up its nucleus to make room. Fighting bacteria is the work of white blood cells. Clotting depends on platelets and plasma proteins. And digestive enzymes come from the pancreas and the gut lining.

The cell membrane contributes to the life of a cell by—

• a.copying the cell's genetic material
• b.controlling which substances enter and leave✓
• c.assembling amino acids into proteins
• d.converting sunlight into chemical energy

The membrane is selectively permeable, admitting some molecules, pumping others out and excluding the rest, which is how a cell keeps its interior different from its surroundings. Copying DNA happens in the nucleus. Capturing sunlight is the chloroplast's job in plants. And protein assembly takes place at the ribosomes.

A book rests on a table and stays there. Which statement best explains why, according to Newton's first law?

• a.No net force is acting on it✓
• b.Its mass has become zero
• c.The table exerts no force at all
• d.Gravity has stopped pulling on it

An object at rest stays at rest unless a net force acts, and here gravity pulling down is exactly balanced by the table pushing up, so the forces sum to zero. Gravity has not stopped; it is being opposed. The table is certainly pushing, and that push is half the balance. And the book's mass is unchanged, which is why gravity still acts on it.

A swimmer pushes backward against the water and moves forward. This illustrates Newton's third law because—

• a.the swimmer's mass increases in water
• b.the water pushes forward with equal force✓
• c.force and motion are unrelated in fluids
• d.water offers no resistance to motion

Forces come in pairs: the swimmer's push on the water is matched by the water's push on the swimmer, equal in size and opposite in direction, and that second force is what drives her forward. Water plainly does resist motion, which is why swimming is work. Mass does not change in water, though buoyancy changes apparent weight. And force and motion are tightly related here, as the third law says.

A net force of 20 newtons acts on a 4-kilogram cart. What is the cart's acceleration?

• a.24 m/s²
• b.0.2 m/s²
• c.5 m/s²✓
• d.80 m/s²

Newton's second law gives acceleration as force divided by mass, so 20 N ÷ 4 kg = 5 m/s². Multiplying instead of dividing gives 80 and reverses the relationship. Adding the two numbers gives 24, which mixes incompatible units. And dividing the mass by the force gives 0.2, the reciprocal of the right calculation.

Velocity differs from speed because velocity also states—

• a.the distance that was covered
• b.the direction of the motion✓
• c.the time the trip required
• d.the mass of the moving object

Speed is how fast something moves; velocity is how fast and which way, which is why two cars at the same speed in opposite directions have different velocities. Distance and time are the inputs that give speed in the first place. And mass appears in momentum and in force but not in either speed or velocity.

Acceleration is defined as the rate at which—

• a.force is applied
• b.mass is gained
• c.distance increases
• d.velocity changes✓

Acceleration measures how quickly velocity changes, which means an object speeding up, slowing down or merely turning is accelerating. Distance increasing over time is speed, one step back from acceleration. Force is what causes the acceleration rather than the quantity being measured. And mass is not changing in these problems at all.

A worker pushes a crate 3 meters along the floor with a steady force of 10 newtons in the direction of motion. How much work is done?

• a.3.3 joules
• b.13 joules
• c.300 joules
• d.30 joules✓

Work is force times the distance moved in the direction of the force, so 10 N × 3 m = 30 J. Adding the numbers gives 13 and ignores what work means. Dividing gives 3.3 and inverts the relationship. And 300 would require ten times the distance or the force.

A book sitting on a high shelf has energy because of its position. This energy is—

• a.thermal energy
• b.chemical energy stored in molecular bonds
• c.gravitational potential energy✓
• d.the kinetic energy of a moving body

Energy stored by virtue of position in a gravitational field is potential energy, and it converts to motion if the book falls. Kinetic energy belongs to objects that are actually moving, and this one is not. Chemical energy is stored in the bonds of molecules, as in fuel or food. And thermal energy is the energy of random particle motion, measured as temperature.

A swinging pendulum slows and finally stops. The law of conservation of energy says that its energy—

• a.was never present in the system
• b.turned into additional mass
• c.was destroyed by the friction
• d.changed into heat and sound✓

Energy is not lost but transferred, and friction at the pivot and drag through the air move it into heat and a little sound in the surroundings. Saying friction destroyed it contradicts the law being asked about. The pendulum plainly had energy while it swung. And converting to mass is a relativistic effect utterly negligible here.

In a sealed container, 10 grams of one substance react completely with 4 grams of another. What is the total mass of the products?

• a.6 grams
• b.10 grams
• c.14 grams✓
• d.It cannot be determined

Mass is conserved in a chemical reaction, so the products of a sealed reaction weigh what the reactants weighed: 14 grams. Subtracting gives 6 and treats the reaction as a loss. Reporting 10 keeps only the larger reactant. And the answer is entirely determinable, which is the point of the conservation law.

In the equation 2H2 + O2 -> 2H2O, the coefficient 2 in front of H2O tells you—

• a.how fast the reaction will proceed
• b.how many atoms are in one molecule
• c.how much heat the reaction gives off
• d.how many molecules of water are formed✓

A coefficient counts whole units of the substance, so two water molecules are produced for every oxygen molecule consumed. Atoms within a single molecule are counted by the subscripts, not the coefficient. Heat released is written separately as an energy term or measured in the laboratory. And the rate of reaction depends on conditions the equation does not record.

In an atom, the protons and neutrons are found—

• a.bonded to neighboring atoms
• b.orbiting outside the electron cloud
• c.spread evenly through the whole atom
• d.packed together in the nucleus✓

Almost all of an atom's mass sits in a tiny central nucleus made of protons and neutrons, with electrons occupying the far larger volume around it. An even spread through the atom was an early model that scattering experiments ruled out. Nothing orbits outside the electrons; they are the outermost part. And bonding involves electrons, not the nucleus.

The atomic number of an element equals the number of—

• a.bonds the atom can form
• b.particles in the nucleus
• c.protons in the nucleus✓
• d.neutrons in the nucleus

Atomic number counts protons, and it is what identifies the element: change it and you have a different element. Neutron number varies among isotopes of the same element, so it cannot be the identifier. Protons plus neutrons together give the mass number instead. And bonding capacity follows from the electron arrangement.

Two atoms are isotopes of the same element. They have—

• a.the same neutrons but different protons
• b.no neutrons in either nucleus
• c.different numbers of both particles
• d.the same protons but different neutrons✓

Isotopes share the proton count that defines the element and differ in neutrons, which makes them differ in mass while behaving almost identically in chemical reactions. Differing in protons would make them different elements altogether. Differing in both would likewise change the element. And only the lightest hydrogen isotope has no neutron, which is a special case rather than the definition.

An atom becomes an ion when it—

• a.joins with an identical atom
• b.is heated above its boiling point
• c.gains or loses one or more electrons✓
• d.gains or loses one or more protons

An ion is a charged atom, and charge appears when the number of electrons no longer balances the number of protons. Changing the proton count would change the element, which is a nuclear event rather than ionization. Heating can eventually strip electrons, but boiling alone does not make ions. And two identical atoms joining form a molecule, which is neutral.

Elements in the same column of the periodic table tend to—

• a.contain the same number of protons
• b.have the same atomic mass
• c.react in similar ways✓
• d.exist only as gases

A column, or group, collects elements with the same number of outer electrons, and since bonding is done by those electrons the group members behave alike chemically. Atomic mass rises steadily down a column rather than repeating. Only one group is entirely gaseous, so that cannot be a general rule. And identical proton counts would make them the same element.

A solution with a pH of 3 is—

• a.basic
• b.neutral
• c.saturated
• d.acidic✓

The pH scale runs from strongly acidic to strongly basic with 7 as neutral, so a reading of 3 lies well on the acidic side. Basic solutions read above 7. Neutral is 7 exactly, as pure water is at room temperature. And saturation describes how much solute a solution holds, which pH does not measure.

When an acid and a base are mixed in the right proportions, the products are—

• a.an alcohol and heat
• b.a salt and water✓
• c.two new acids
• d.a metal and a gas

Neutralization pairs the acid's hydrogen ions with the base's hydroxide ions to make water, leaving the remaining ions as a dissolved salt. No metal is produced, although many salts contain a metal ion that was already present. Alcohols come from quite different reactions, and heat is released but is not a product in the chemical sense. And the acidity is consumed rather than doubled.

Stirring sugar into warm water until it disappears is a physical change because—

• a.the sugar keeps its chemical identity✓
• b.the mixture cannot be separated
• c.the water molecules break apart
• d.a new compound has been created

The sugar is dispersed among the water molecules but is still sugar, which is why evaporating the water recovers it unchanged. No new compound formed, and that is exactly what distinguishes this from a chemical change. Water molecules are not broken apart by dissolving anything. And the mixture can be separated, by evaporation or distillation.

Compared with a liquid, the particles of a gas—

• a.spread out to fill their container✓
• b.are locked into a fixed pattern
• c.move more slowly at the same heat
• d.occupy a fixed volume of their own

Gas particles are far apart and move freely, so a gas expands until it meets the walls of whatever holds it. A fixed repeating pattern describes a solid, at the other end of the scale. At the same temperature gas particles move faster than those in a liquid, not slower. And having a definite volume is a property of solids and liquids, not gases.

Ice at 0 °C is heated and begins to melt. While melting continues, the temperature of the ice-water mixture—

• a.falls below 0 °C
• b.rises then falls back
• c.rises steadily
• d.stays at 0 °C✓

Energy added during a change of state goes into breaking the bonds that hold the solid together rather than into faster particle motion, so the thermometer holds steady until the last ice is gone. A steady rise is what happens before melting starts and after it finishes. Falling below freezing would require removing heat. And there is no reason for the temperature to reverse.

An object placed in water floats. This tells you that the object's density is—

• a.less than the density of water✓
• b.unrelated to the density of water
• c.greater than the density of water
• d.equal to the density of water

Floating means the object displaces a weight of water greater than its own, which happens when it is less dense than the fluid. Greater density is what makes something sink. Equal density leaves an object suspended, neither rising nor settling. And the comparison is the whole explanation, so the two densities are anything but unrelated.

A metal spoon left in a pot of hot soup becomes hot along its handle. The heat travels mainly by—

• a.convection
• b.conduction✓
• c.evaporation
• d.radiation

Conduction moves energy through direct contact as fast-moving particles jostle their neighbors along the solid metal. Convection needs a fluid to circulate, which the spoon is not. Radiation would warm the handle without contact and is a minor effect here. And evaporation removes energy from the soup's surface rather than carrying it up the handle.

Copper is used for household wiring because it is—

• a.a good insulator of electricity
• b.lighter than every other metal
• c.a good conductor of electricity✓
• d.unable to carry a magnetic field

Copper's loosely held outer electrons move easily, so current passes with little energy wasted as heat, which is what a wire is for. An insulator is the opposite and is used for the covering, not the core. Copper is not especially light; aluminum is lighter and is sometimes used for that reason. And its magnetic behavior is not why it was chosen.

Three bulbs are wired in a single series loop. If one bulb burns out, the others—

• a.flicker but stay lit
• b.go out as well✓
• c.shine more brightly
• d.stay lit as before

A series circuit offers current only one path, so a break anywhere stops the current everywhere and every bulb goes dark. Staying lit is what happens in a parallel circuit, where each branch is independent. Brightening would require more current, and there is none. And flickering implies an intermittent connection rather than a burnt-out filament.

A 12-volt battery drives a current through a 3-ohm resistor. What is the current?

• a.4 amperes✓
• b.15 amperes
• c.36 amperes
• d.0.25 amperes

Ohm's law gives current as voltage divided by resistance, so 12 V ÷ 3 Ω = 4 A. Multiplying gives 36 and confuses the relationship. Adding gives 15 and mixes units that cannot be added. And dividing resistance by voltage gives 0.25, the reciprocal of the correct result.

Two bar magnets are brought together north pole to north pole. They will—

• a.push each other apart✓
• b.pull each other together
• c.swap their poles
• d.lose their magnetism

Like poles repel, so two north poles pressed toward each other resist, and releasing them lets them fly apart. Attraction happens between a north pole and a south pole. Magnetism can be lost by heating or hammering but not by this. And a magnet's poles do not trade places because another magnet is nearby.

For waves traveling at the same speed, a wave with a higher frequency has—

• a.a greater amplitude
• b.a shorter wavelength✓
• c.a longer wavelength
• d.a lower speed

Speed equals frequency times wavelength, so at fixed speed the two must trade off and more waves per second means each is shorter. A longer wavelength accompanies a lower frequency. Amplitude is the height of the wave and varies independently of frequency. And the speed was given as unchanged.

A ringing bell is sealed in a jar and the air is pumped out. The sound fades away because sound—

• a.needs matter to travel through✓
• b.changes into light in a vacuum
• c.is absorbed by the glass jar
• d.travels faster in empty space

Sound is a mechanical wave: it propagates as particles of a medium push on their neighbors, and with no air left there is nothing to carry it. It does not travel faster in a vacuum; it does not travel at all. The glass was there before the air was removed and did not silence the bell. And sound does not convert into light.

A straw in a glass of water looks bent at the surface. This happens because light—

• a.is absorbed by the clear water
• b.changes direction entering the water✓
• c.bounces off the water's surface
• d.travels in a curved path in water

Light slows and bends as it crosses from water into air, so the rays reaching your eye arrive from a different apparent direction and the straw appears displaced. Bouncing off the surface is reflection, which produces an image on the water rather than a bend in the straw. Clear water absorbs very little visible light. And within the water the light travels in straight lines; only the boundary bends it.

Igneous rock forms when—

• a.heat and pressure reshape an existing rock
• b.flowing water wears away a rock face
• c.molten rock cools and hardens✓
• d.layers of sediment are pressed together

Igneous rock is solidified melt, whether it cools slowly underground into coarse crystals or quickly at the surface into fine ones. Compacted sediment produces sedimentary rock instead. Heat and pressure altering an existing rock without melting it produce metamorphic rock. And water wearing away rock is erosion, which makes sediment rather than rock.

In an undisturbed sequence of sedimentary layers, the oldest layer is normally—

• a.impossible to locate
• b.at the bottom✓
• c.in the middle
• d.at the top

Sediment settles from above, so each new layer rests on older material and the sequence reads oldest upward, a rule geologists call superposition. The topmost layer is the youngest. The middle is intermediate in age rather than oldest. And the age order is entirely readable so long as the layers have not been overturned by later folding.

Most of the world's earthquakes occur—

• a.near the center of the largest continents
• b.in the deepest parts of the ocean basins
• c.where the crust is thickest and oldest
• d.along the boundaries between tectonic plates✓

Plates grind past, pull away from and push under one another at their edges, and the sudden slip that releases the accumulated strain is an earthquake, which is why seismic maps trace out the plate boundaries. Continental interiors are comparatively quiet. Great ocean depth marks trenches, which are themselves plate boundaries, but depth is not the cause. And thick old crust is among the most stable ground there is.

A chain of volcanoes forms above a subduction zone because—

• a.the ocean floor is being lifted upward
• b.the descending plate melts material at depth✓
• c.two plates are pulling apart at the surface
• d.erosion has exposed old volcanic rock

As one plate sinks beneath another it carries water down, lowering the melting point of the rock above it, and the magma that forms rises to build volcanoes in an arc. Plates pulling apart create ridges and rift valleys, a different setting. Uplift of the sea floor produces mountains without necessarily producing magma. And erosion can expose volcanic rock but cannot create an active chain.

In the water cycle, the release of water vapor from the leaves of plants is called—

• a.transpiration✓
• b.condensation
• c.infiltration
• d.precipitation

Transpiration is the movement of water up through a plant and out through its leaves, and over a forest it returns an enormous volume to the air. Condensation is vapor turning back into liquid, which forms clouds. Precipitation is that water falling as rain or snow. And infiltration is water soaking down into the ground.

The passage of a cold front over a region is typically followed by—

• a.cooler air and often brief storms✓
• b.clear skies with no change in air
• c.a long period of steady warming
• d.a rise in humidity that lasts weeks

A cold front is the leading edge of advancing cold air that shoves warm moist air upward, which commonly triggers showers or thunderstorms along the boundary and leaves cooler, drier air behind. Steady warming describes a warm front instead. Some change always accompanies a front, which is what makes it a front. And humidity generally falls after the front passes rather than climbing for weeks.

Carbon dioxide is called a greenhouse gas because it—

• a.traps heat radiating from the Earth✓
• b.blocks sunlight from reaching the ground
• c.reflects heat back out into space
• d.destroys ozone in the upper atmosphere

Carbon dioxide lets visible sunlight through but absorbs the longer-wave infrared the warmed surface radiates, and re-emitting some of it downward keeps the lower atmosphere warmer than it would otherwise be. It does not block incoming sunlight, which is how the surface gets warm in the first place. Ozone destruction is caused by other compounds entirely. And reflecting heat away would cool the planet, the opposite of the effect.

Earth has seasons mainly because—

• a.its axis is tilted as it orbits the Sun✓
• b.its distance from the Sun changes greatly
• c.it spins more slowly in winter months
• d.the Sun's output rises and falls yearly

The tilt means each hemisphere leans toward the Sun for part of the year and away for the rest, changing the angle of the sunlight and the length of the day. Earth's distance from the Sun does vary slightly, but far too little to drive the seasons, and it would give both hemispheres the same season at once. The Sun's output is nearly steady. And the rotation rate does not change with the calendar.

The phases of the Moon are caused by—

• a.clouds in the Earth's atmosphere
• b.the rotation of the Moon on its own axis each month
• c.the changing positions of the Sun, Earth and Moon✓
• d.the Earth's shadow falling across the face of the Moon

Half the Moon is always lit; what changes is how much of that lit half faces us, and that depends on where the Moon is in its orbit relative to the Sun and Earth. Earth's shadow on the Moon is a lunar eclipse, which happens occasionally rather than monthly. Clouds hide the Moon without changing its phase. And the Moon's rotation keeps one face toward Earth and does not produce the cycle.

Ocean tides on Earth are caused mainly by—

• a.prevailing winds over the ocean
• b.the Moon's gravitational pull✓
• c.the Earth's magnetic field
• d.differences in ocean salt content

The Moon's gravity pulls hardest on the water nearest it and least on the far side, raising bulges that sweep around as the Earth rotates; the Sun contributes a smaller share. Winds pile up water in storm surges but do not produce the twice-daily rhythm. The magnetic field does not move water. And salinity differences drive slow deep currents, not tides.

The Sun is best classified as—

• a.a star✓
• b.a galaxy
• c.a comet
• d.a planet

The Sun is a star, a ball of gas generating energy by fusing hydrogen in its core, and it is ordinary except for being close. A planet orbits a star and shines only by reflected light. A comet is a small icy body on a long orbit. And a galaxy contains billions of stars, so the Sun is one member of ours rather than a galaxy itself.

A light-year is a unit of—

• a.brightness
• b.time
• c.distance✓
• d.mass

A light-year is how far light travels in one year, which makes it a measure of distance despite the word year in its name. Time is measured in seconds and years themselves. Brightness is reported as magnitude or luminosity. And mass is given in kilograms or in solar masses.

Which layer of the Earth lies directly beneath the crust?

• a.The atmosphere
• b.The inner core
• c.The outer core
• d.The mantle✓

The mantle is the thick layer of hot rock between the thin crust and the core, and its slow motion is what drags the plates around. The outer core lies beneath the mantle and is liquid metal. The inner core is deeper still and solid. And the atmosphere sits above the crust rather than below it.

A deep canyon with a river running along its floor was most likely shaped by—

• a.a single earthquake event
• b.erosion by running water✓
• c.the eruption of a volcano
• d.the weight of a glacier melting

Running water cuts downward over long spans of time, carrying away rock and deepening its own channel, which is the standard explanation for a river canyon. An earthquake can open a fissure but does not carve a valley with a river in it. Volcanic eruptions build landforms up. And glaciers do carve valleys, but they leave broad U-shaped troughs rather than a narrow canyon cut by a stream.

Coal, oil and natural gas are called fossil fuels because they formed from—

• a.minerals crystallizing out of seawater
• b.volcanic ash settling on the sea floor
• c.rainwater collecting in deep rock layers
• d.the remains of organisms buried long ago✓

Fossil fuels are the altered remains of plants and microscopic marine life buried under sediment and cooked by heat and pressure across millions of years, which is why they are not replaced on any human timescale. Minerals precipitating from seawater form evaporite deposits such as salt. Volcanic ash forms tuff. And water in deep rock is groundwater, not fuel.

Which principle allows a federal court to refuse to enforce a law it finds contrary to the Constitution?

• a.Executive privilege
• b.Judicial review✓
• c.Eminent domain
• d.Popular sovereignty

Judicial review is the power of the courts to measure a statute against the Constitution and decline to apply it if the two conflict; the Supreme Court claimed the power for itself in Marbury v. Madison in 1803. Executive privilege is a President's claim to withhold certain communications, which is about secrecy rather than constitutionality. Eminent domain is the government's power to take private property for public use with compensation. Popular sovereignty is the idea that authority comes from the people, a source of legitimacy rather than a judicial power.

An amendment to the U.S. Constitution takes effect only after it is ratified by—

• a.the President and the Senate
• b.three-fourths of the states✓
• c.a simple majority in Congress
• d.a national vote of the people

Article V sends a proposed amendment to the states, and it becomes part of the Constitution only when three-fourths of them ratify it, whether through their legislatures or through conventions. Congress proposes by two-thirds of both houses, so a simple majority there is not even enough to start the process. There is no national referendum on amendments anywhere in the Constitution. And the President has no role at all: an amendment is not a bill and is never presented for signature.

Congress can pass a bill over the President's veto with a vote of—

• a.three-fourths of each house
• b.a majority of each house
• c.two-thirds of each house✓
• d.two-thirds of the Senate only

Article I, Section 7 requires two-thirds of each chamber to override a veto, which is why a President with a third of either house behind him is hard to defeat. A simple majority is what passed the bill in the first place and was plainly not enough. Three-fourths is the bar for ratifying an amendment, a different and higher threshold. And the House cannot be skipped: both chambers must reach two-thirds.

Which power does the Constitution give to Congress rather than to the President?

• a.Negotiating a treaty
• b.Nominating a federal judge
• c.Pardoning a federal offense
• d.Declaring war on another nation✓

Article I lists the power to declare war among Congress's powers, and it has never belonged to the President, who commands the forces once they are committed. The pardon power for federal offenses is the President's alone under Article II. Treaties are negotiated by the President, with the Senate then giving or withholding consent. And judicial nominations are made by the President, again with the Senate confirming.

Which chamber of Congress votes on whether to confirm the President's nominees to the federal courts?

• a.The House of Representatives
• b.The Electoral College
• c.The Supreme Court
• d.The Senate✓

The Senate holds the advice-and-consent power, so a judicial nominee reaches the bench only after a Senate vote. The House has no part in confirmations; its distinctive powers are originating revenue bills and voting articles of impeachment. The Supreme Court does not choose its own members. And the Electoral College exists only to elect the President and Vice President, then dissolves.

A candidate wins the presidency by receiving—

• a.two-thirds of the electoral votes
• b.the largest share of the popular vote
• c.a majority of the state legislatures
• d.a majority of the electoral votes✓

The Constitution decides the presidency in the Electoral College, and a candidate needs more than half of the electors, not merely more than any rival. Leading the national popular vote is not the legal test, which is why a candidate can win the country and lose the office. Two-thirds is the threshold for a veto override or for proposing an amendment, not for election. And state legislatures appoint electors but cast no vote for President themselves.

The Tenth Amendment provides that powers not given to the federal government are—

• a.surrendered by every level of government
• b.reserved to the states and the people✓
• c.granted to the President in emergencies
• d.held jointly by Congress and the courts

The Tenth Amendment is the textual home of federalism: what the Constitution does not delegate to the United States, and does not forbid to the states, stays with the states or with the people. It does not hand leftover power to Congress and the courts, which are two of the federal bodies the amendment is limiting. It creates no emergency reservoir for the President. And it does not extinguish the powers; it locates them.

If the President neither signs nor vetoes a bill within ten days while Congress is in session, the bill—

• a.becomes law without a signature✓
• b.is treated as though it had been vetoed
• c.returns to the committee that wrote it
• d.must be voted on again

Article I, Section 7 says that a bill not returned within ten days, Sundays excepted, becomes law as if it had been signed, provided Congress is still sitting. Silence counts as a veto only when Congress has adjourned in the meantime, which is the pocket veto and the opposite case. Nothing sends the bill back to committee; it has already passed both chambers. And no second vote is required, because no veto message ever arrived.

Which protection is written into both the Fifth Amendment and the Fourteenth Amendment?

• a.The right to bear arms
• b.Due process of law✓
• c.Protection against unreasonable searches
• d.Freedom of the press

Both amendments forbid depriving a person of life, liberty, or property without due process of law: the Fifth binds the federal government and the Fourteenth binds the states. Freedom of the press appears only in the First Amendment. The right to bear arms appears only in the Second. And protection against unreasonable searches and seizures is the Fourth Amendment's alone, though the Court has since applied it to the states through the Fourteenth.

Under the Fourth Amendment, police generally need a warrant supported by probable cause in order to—

• a.question a willing witness
• b.search a private home✓
• c.arrest someone for a public crime
• d.write a traffic citation

The home sits at the center of the Fourth Amendment, and entering one to search it normally requires a warrant issued on probable cause. Talking to a witness who agrees to talk involves no search or seizure at all. An arrest for an offense an officer sees in public may be made without a warrant. And a citation for a traffic violation the officer observed is likewise no search of anything.

Which of these is a check that the other branches hold over the federal judiciary?

• a.Judges are nominated by the President and confirmed by the Senate✓
• b.The President may veto a bill that both houses of Congress passed
• c.Congress may impeach and remove the President
• d.The Court may decide that a statute Congress passed is unconstitutional

Federal judges do not choose themselves: the President nominates and the Senate confirms, which is how the elected branches shape the courts. The veto is the President's check on Congress, running in a different direction entirely. Impeachment of the President is Congress checking the executive. And striking down a statute is the judiciary checking the other two, which is the reverse of what the question asks.

The Nineteenth Amendment, ratified in 1920—

• a.lowered the voting age to eighteen
• b.guaranteed equal protection of the laws
• c.abolished slavery in the United States
• d.barred denying the vote on account of sex✓

The Nineteenth Amendment forbids the United States or any state from denying or abridging the right to vote on account of sex, which is how women secured the ballot nationally. Slavery was abolished by the Thirteenth Amendment in 1865. The voting age was lowered to eighteen by the Twenty-Sixth Amendment in 1971. And equal protection of the laws comes from the Fourteenth Amendment, ratified in 1868.

The main purpose of a party's primary election is to—

• a.choose the officials who run the party organization nationally
• b.choose that party's nominee for the general election✓
• c.settle what the party's platform will say for four years
• d.count each state's electoral votes

A primary is an intra-party contest whose whole function is to decide which candidate carries the party's label into the general election. Electoral votes are counted by Congress long after the general election and have nothing to do with a primary. A party picks the officials who run its national organization through its own committees rather than at the ballot box. And the platform is written at the national convention rather than voted on by primary voters.

Which official heads the executive branch of a city government?

• a.A state legislator
• b.The governor
• c.The county sheriff
• d.The mayor✓

A mayor is the chief executive of a municipality, the local counterpart of a governor or a President. A governor heads a state, a level above the city. A sheriff is a law enforcement officer, usually elected county-wide, and runs one department rather than the city. And a state legislator makes state law and holds no executive office at all.

Who has the power to veto a bill passed by a state legislature?

• a.The President of the United States
• b.The governor of that state✓
• c.The mayor of the largest city
• d.The state supreme court

State constitutions give the governor a veto over bills the legislature has passed, mirroring the President's role at the federal level. A mayor's authority stops at the city limits and never reaches a state bill. A state supreme court may later hold a law invalid, but that is judicial review after enactment, not a veto. And the President has no power over state legislation whatsoever.

To say that the U.S. Congress is bicameral means that—

• a.its members serve two-year terms
• b.it shares power with two other branches
• c.it meets in session twice a year
• d.it is made up of two separate chambers✓

Bicameral describes a legislature built out of two houses, here the House of Representatives and the Senate, each of which must pass a bill before it can become law. The two-year term belongs only to House members, and a term length is not what the word describes. The number of sessions in a year is a matter of the calendar, not of structure. And sharing power with two other branches is separation of powers, a different idea altogether.

The census taken every ten years is used to determine—

• a.which states may hold early primaries
• b.how long a representative's term runs
• c.how many House seats each state gets✓
• d.how many senators each state gets

Apportionment is the constitutional purpose of the census: the count decides how the fixed number of House seats is divided among the states, and states gain or lose representation accordingly. Senate membership is set at two per state by the Constitution and no count can change it. A representative's term is fixed at two years. And the primary calendar is arranged by the parties and the states, with no connection to the census.

The process by which a lawful permanent resident becomes a U.S. citizen is called—

• a.ratification
• b.apportionment
• c.appropriation
• d.naturalization✓

Naturalization is the legal process, set by federal statute, through which someone who was not a citizen at birth becomes one. Apportionment is the division of House seats among the states after a census. Ratification is formal approval of a treaty or a constitutional amendment. And appropriation is Congress setting aside money for a purpose.

The House of Representatives votes to impeach a federal officer. Where is the trial then held?

• a.In the Senate✓
• b.In the Electoral College
• c.In a federal district court
• d.In the Supreme Court

Impeachment and removal are split between the chambers: the House brings the charges and the Senate sits as the court that tries them, with conviction requiring two-thirds. The Supreme Court does not try impeachments, although the Chief Justice presides when the President is the officer charged. A district court hears ordinary federal cases, not impeachments. And the Electoral College has no judicial function of any kind.

The establishment clause of the First Amendment bars the government from—

• a.setting up an official religion✓
• b.requiring children to attend school
• c.allowing prayer in private homes
• d.granting licenses to broadcasters

The clause opens the First Amendment by forbidding any law respecting an establishment of religion, which at its core means the government may not install an official faith. Private worship is protected rather than restricted, so permitting it is not a problem the clause addresses. Broadcast licensing is a regulatory matter with no religious dimension. And compulsory school attendance is a state power that the establishment clause does not reach.

A writ of habeas corpus requires the government to—

• a.justify holding a person in custody✓
• b.pay a defendant's legal expenses
• c.bring a case to trial within a year
• d.reveal the identity of an informant

Habeas corpus is the ancient demand that a jailer produce the prisoner and show lawful cause for the detention, which is why it is called the great writ. Paying a defendant's costs is a separate question handled by other rules. Disclosing an informant may be ordered in the course of a criminal case but has nothing to do with the writ. And the pace of a prosecution is governed by speedy-trial rules, not by habeas corpus.

An interest group differs from a political party mainly because an interest group—

• a.seeks to influence policy without nominating candidates✓
• b.must register every one of its members with the government
• c.is forbidden by law from contacting lawmakers about policy
• d.may take positions on only one issue at a time

A party exists to win offices and therefore nominates candidates under its own label; an interest group pursues particular policies and works on whoever holds office. Contacting lawmakers is precisely what interest groups do, and petitioning the government is protected by the First Amendment. Membership rolls are not filed with the government, though lobbying activity itself is often reported. And nothing limits a group to one issue at a time.

Which of these is an example of local public policy?

• a.A federal court interprets a national statute
• b.A city council sets a limit on building heights✓
• c.A company raises the price of its product
• d.A family decides to move to another state

Public policy is a course of action adopted by a government for the community it governs, and a height limit voted by a city council is exactly that at the local level. A family's move is a private decision, however much local policy may have shaped it. A company's pricing is a business decision made in a market, not a governmental act. And a federal court reading a national statute is federal and judicial rather than local policymaking.

The Voting Rights Act of 1965 was aimed chiefly at—

• a.lowering the voting age in federal elections
• b.removing barriers that kept Black citizens from voting✓
• c.setting a single national date for all elections
• d.requiring states to use identical ballot designs

The Act attacked the devices, literacy tests above all, that southern states had used to keep Black citizens off the rolls, and it put federal enforcement behind the Fifteenth Amendment. It did not create a uniform election date; federal election days were already fixed by earlier law. It said nothing about ballot design, which remains a state matter. And the voting age was lowered later, by the Twenty-Sixth Amendment in 1971.

The Great Compromise of 1787 settled a dispute over—

• a.how the states would be represented in Congress✓
• b.whether a bill of rights would be added
• c.how federal judges would be appointed
• d.how the President would be chosen by electors

Large and small states deadlocked over representation, and the compromise gave population its due in the House while giving every state two seats in the Senate. The method of electing the President was worked out separately in the Electoral College provisions. A bill of rights was rejected at the convention and added afterward as the first ten amendments. And judicial appointments were never the subject of that particular bargain.

In Federalist No. 51, James Madison wrote that 'ambition must be made to counteract ambition.' He was defending—

• a.the admission of new western states
• b.a single strong national executive
• c.checks and balances among the branches✓
• d.the direct election of senators

Madison's argument is that each branch must be given the motive and the means to resist encroachment by the others, which is the case for checks and balances rather than for trusting officeholders to be virtuous. Direct election of senators came far later, with the Seventeenth Amendment in 1913. A single strong executive is argued elsewhere in the Federalist and is not what this sentence is about. And the admission of new states is not a subject of Federalist No. 51 at all.

Article VI provides that the Constitution and federal laws made under it 'shall be the supreme Law of the Land.' This means that—

• a.the states may not write constitutions
• b.state courts may not hear federal claims
• c.federal law needs no state enforcement
• d.a conflicting state law must give way✓

The supremacy clause settles conflicts in favor of valid federal law, so a state statute that cannot be squared with it is unenforceable. It does not close state courts to federal questions; state judges are expressly bound to apply federal law. Every state has its own constitution, and nothing in Article VI forbids that. And a great deal of federal law is in fact carried out with state cooperation.

The Fourteenth Amendment forbids a state to 'deny to any person within its jurisdiction the equal protection of the laws.' A state law that did what would raise a question under this clause?

• a.Create a new court of appeals
• b.Raise the state sales tax by one cent
• c.Treat two groups of residents differently✓
• d.Move an election from spring to autumn

Equal protection is about classification: the clause is triggered when a law sorts people into groups and treats them unlike one another. A uniform tax increase applies to everyone alike and raises no such question. Shifting an election date is a scheduling choice with no classification in it. And adding a court of appeals reorganizes the judiciary without treating any person differently.

In Brown v. Board of Education (1954) the Supreme Court held that—

• a.separate public facilities may be kept equal
• b.public schools must be funded by the states
• c.segregated public schools are unconstitutional✓
• d.school attendance may be made compulsory

The Court held that separating schoolchildren by race denies equal protection, and in doing so it rejected the separate-but-equal rule of Plessy v. Ferguson for public education. Keeping separate facilities equal was the doctrine Brown overturned, not what it announced. Funding schools is a state matter the case did not address. And compulsory attendance laws long predated the decision and were not at issue.

Which action would violate the separation of powers?

• a.A President vetoing a spending bill Congress passed
• b.The Senate rejecting a nominee for a cabinet office
• c.Congress holding hearings on an agency
• d.A federal judge writing a new criminal statute✓

Writing statutes is the legislative power, so a judge who created a crime on his own authority would be exercising a power the Constitution gives to Congress. A veto is an express constitutional power of the President. Rejecting a nominee is the Senate exercising advice and consent. And congressional oversight hearings are a recognized legislative check on the executive branch.

The Twenty-Second Amendment limits a President to—

• a.three elected terms
• b.one six-year term
• c.two elected terms✓
• d.ten years in office

The amendment, ratified in 1951 after Franklin Roosevelt's four elections, bars anyone from being elected President more than twice. A single six-year term has been proposed at times but never adopted. Three terms is more than the amendment allows. And while a successor who finishes part of another's term can serve up to ten years, the limit the amendment states is on elections, not a flat number of years.

Which power belongs to the federal government alone?

• a.Chartering local schools
• b.Setting up traffic courts
• c.Coining money✓
• d.Issuing driver's licenses

The Constitution gives Congress the power to coin money and forbids the states to do it, which makes currency an exclusively federal matter. Driver's licensing is run entirely by the states, which is why the rules differ across state lines. Schools are chartered under state law and administered locally. And traffic courts are creatures of state and local judicial systems.

A group that gathers voter signatures to put a proposed law directly on the ballot is using—

• a.an impeachment petition
• b.the initiative process✓
• c.the recall of an official
• d.a legislative referendum

An initiative lets citizens themselves place a measure before the voters by petition, and many states provide for it in their constitutions. A recall also begins with signatures but its object is removing an officeholder, not enacting a law. A referendum is referred to the voters by the legislature rather than gathered by citizens. And impeachment is a legislative proceeding with no petition or ballot step.

A campaign advertisement paid for by a candidate is best treated as—

• a.a neutral summary of a public record
• b.a secondary source written by a scholar
• c.a persuasive source presenting one side✓
• d.an official document of the government

The sponsor wants a vote, so the advertisement selects whatever helps and omits whatever does not, which makes it evidence of the candidate's argument rather than a balanced account. It is not neutral, precisely because the person it describes paid for it. It is not scholarship, which is written to be checked by other scholars. And it is not a government document; a campaign is a private organization.

In a unitary system of government—

• a.power is divided between two sovereign levels
• b.the national government holds the main authority✓
• c.the states may leave the union at will
• d.the courts hold authority over the legislature

A unitary state concentrates authority nationally and creates local units that exercise whatever power the center grants them and may withdraw. Dividing sovereignty between a national and a state level is federalism, the contrast the question is drawing. A right to secede belongs to a confederation, and even there it is a matter of the compact. And judicial supremacy over the legislature describes a relationship among branches rather than a distribution of power between levels.

In an authoritarian one-party state, elections are usually—

• a.held with no real competition allowed✓
• b.held more frequently than elsewhere
• c.used to choose among rival parties
• d.decided by an independent judiciary

Such a state may hold elections and count votes, but rival parties are banned or crippled, so the outcome is settled before polling day and the vote serves to display support rather than to allocate power. Courts in these systems are usually controlled rather than independent, and in any event judges do not decide elections. Frequency is not what distinguishes the system. And choosing among rival parties is the one thing the arrangement prevents.

Which is the strongest reason a historian would treat a soldier's wartime letter home as a primary source?

• a.It agrees with most later accounts of the war
• b.It was written during the events by a participant✓
• c.It was published by a university press
• d.It contains no obvious factual errors

What makes a source primary is its position in time and its author's relation to the events, and a soldier writing home satisfies both. Agreement with later accounts is a question of reliability, and an unreliable letter is still a primary source. The publisher matters not at all to the classification. And being free of error is likewise about accuracy rather than about when and by whom the document was made.

The colonial slogan 'no taxation without representation' objected to—

• a.taxes laid by a Parliament the colonies did not elect✓
• b.taxes used to pay for local roads
• c.any tax whatever laid on goods imported into the colonies
• d.taxes voted and collected by their own colonial assemblies

The grievance was about consent: colonists accepted taxation by legislatures they chose and denied that a Parliament three thousand miles away, containing no member they had elected, could tax them. Taxes voted by their own assemblies were exactly what they defended. The objection was not to import duties as such, since colonial governments levied them too. And the purpose of the money was not the point; who imposed it was.

The Louisiana Purchase of 1803—

• a.added Florida to the United States
• b.ended British claims in the Pacific Northwest
• c.opened California to American settlement
• d.roughly doubled the size of the United States✓

Jefferson bought the Louisiana territory from France, and the acquisition about doubled the national territory while securing the port of New Orleans and the Mississippi trade. Rival claims in the Pacific Northwest were settled later by treaty with Britain. California came from Mexico decades afterward. And Florida was acquired from Spain in a separate treaty in 1819.

The Missouri Compromise of 1820—

• a.paired a slave state with a free state to keep the Senate balanced✓
• b.abolished slavery in the southern states
• c.granted statehood to the whole of the Louisiana Purchase at one stroke
• d.brought the Atlantic trade in enslaved people to an end by federal law

Congress admitted Missouri with slavery and Maine without it, preserving the even number of slave and free states in the Senate, and drew a line across the rest of the Louisiana Purchase. The Atlantic slave trade had already been prohibited by federal law in 1808. The territory was admitted as states gradually over many decades, not all at once. And abolition in the South came only with the Thirteenth Amendment in 1865.

The Emancipation Proclamation of 1863 declared free—

• a.enslaved people in the states then in rebellion✓
• b.enslaved people in the border states alone
• c.every enslaved person in the United States
• d.only those who enlisted in the Union army

Lincoln issued the proclamation as a war measure, and it reached the enslaved population of the areas still in rebellion rather than the whole country. It did not free everyone: slavery in the loyal border states was untouched and ended later by amendment. Enlistment was encouraged by the policy but was never the condition of freedom. And the border states were the one place the proclamation deliberately left alone.

The Fifteenth Amendment, ratified in 1870—

• a.made freed people citizens of the states
• b.barred denying the vote on account of race✓
• c.ended the system of racial segregation
• d.gave women the right to vote nationally

The amendment forbids the United States and the states from denying or abridging the right to vote on account of race, color, or previous condition of servitude, though states found devices to evade it for nearly a century. Women's suffrage came with the Nineteenth Amendment in 1920. Segregation was not ended by any Reconstruction amendment and persisted by law into the 1960s. And citizenship for the freed people was conferred by the Fourteenth Amendment two years earlier.

The Homestead Act of 1862 encouraged western settlement by—

• a.offering public land to settlers who farmed it✓
• b.paying railroads to carry settlers free
• c.buying farmland back from private owners
• d.exempting western settlers from federal law

The Act let a settler claim a parcel of public land and gain title by living on it and cultivating it for a period of years, which drew hundreds of thousands onto the plains. Railroads did receive enormous federal land grants, but that was separate legislation and not free passage for settlers. The government was giving land away here, not purchasing it. And no settler was ever exempted from federal law.

Between the 1890s and the 1920s, Ellis Island in New York Harbor served mainly as—

• a.a customs house for imported cargo
• b.a military fort guarding the sea approaches to the harbor
• c.the chief inspection station for arriving immigrants✓
• d.a prison where immigrants denied entry served sentences

Ellis Island was the federal immigrant inspection station through which millions of new arrivals, mostly from Europe, were processed and either admitted or turned back. It was not a fort; harbor defense sat elsewhere. A small number of arrivals were detained there while their cases were decided, but the island was a processing station rather than a prison. And cargo was cleared through customs houses on the mainland.

In the Progressive Era, writers known as muckrakers were mainly—

• a.journalists exposing corruption and unsafe conditions✓
• b.editors opposing the expansion of suffrage
• c.government officials who defended the railroad companies
• d.novelists writing romantic stories of the frontier past

Muckrakers were investigative journalists whose reporting on political machines, industrial practices and slum conditions built the public pressure behind Progressive reforms. Frontier fiction belonged to a different literary current entirely. The muckrakers attacked large corporations rather than speaking for them. And they generally supported broadening the vote, not restricting it.

The United States entered the First World War in—

• a.1919, just before the peace conference
• b.1916, immediately after a declaration
• c.1914, at the very start of the fighting
• d.1917, nearly three years after it began✓

The war began in Europe in 1914 and the United States stayed formally neutral until Congress declared war in April 1917, with unrestricted submarine warfare the immediate cause. It was not in from the beginning; that is the point of the long neutrality debate. By 1919 the fighting had stopped and the Paris conference was writing the peace. And 1916 was an election year fought partly on staying out.

The Social Security Act of 1935 created—

• a.old-age benefits paid for by payroll taxes✓
• b.a national health insurance program
• c.a guaranteed job for every applicant
• d.federal ownership of the largest banks

The Act set up a contributory system in which taxes on wages fund retirement benefits, along with unemployment insurance and aid to certain groups, and it remains the largest surviving New Deal program. National health insurance was discussed in the 1930s but not enacted. The banks were regulated and insured rather than nationalized. And although New Deal agencies employed millions, no statute guaranteed a job to anyone who asked.

The Japanese attack on Pearl Harbor on December 7, 1941—

• a.ended the fighting in the Pacific theater of the war
• b.opened a Japanese occupation of the Hawaiian islands
• c.brought the United States into the Second World War✓
• d.followed an American declaration of war

The attack on the Pacific Fleet ended the argument over neutrality, and Congress declared war the next day. It opened the Pacific war rather than ending it; the fighting there ran until 1945. Hawaii was never occupied, and the raid was a naval and air strike, not an invasion. And the declaration came after the attack, which is what made it so decisive politically.

The Marshall Plan of 1948 was designed to—

• a.resettle refugees in the United States
• b.collect war reparations from defeated nations
• c.create a permanent military alliance in Europe
• d.help rebuild the economies of western Europe✓

The plan sent American money and goods to help western European economies recover, on the view that prosperity there would resist communist appeal and sustain trade. The military alliance came separately with the founding of NATO in 1949. Reparations ran the other way and were not its purpose. And it was aid sent to Europe rather than a program of resettlement here.

The Montgomery bus boycott of 1955 and 1956 was a protest against—

• a.a rise in the price of bus fares
• b.segregated seating on city buses✓
• c.a tax on public transportation
• d.the closing of a city bus line

Black residents of Montgomery stayed off the buses for more than a year to protest a segregated seating system, after Rosa Parks was arrested for refusing to give up her seat, and the campaign ended when the Supreme Court let stand a ruling against the practice. Fares were not the issue. No line had been closed. And no transportation tax was involved.

The GI Bill, passed in 1944, helped returning veterans mainly by—

• a.paying for schooling and backing home loans✓
• b.exempting them from all federal taxes
• c.granting them land in the western states
• d.guaranteeing them their former jobs back

The Servicemen's Readjustment Act paid tuition and living costs for veterans in school and guaranteed mortgages for them, which expanded both college enrollment and suburban home ownership after the war. Reemployment rights came from separate wartime legislation. Land grants to settlers belonged to the nineteenth century. And veterans received no blanket exemption from taxation.

The opportunity cost of a choice is—

• a.the money actually paid for the item
• b.the tax charged on the transaction
• c.the value of the best option given up✓
• d.the total of all options not chosen

Opportunity cost measures what you gave up, which is the single most valuable alternative you passed over, and it is why a free afternoon spent one way still has a cost. The cash price is an accounting cost and may be zero while the opportunity cost is large. A tax is one component of price, not the concept. And adding up every rejected alternative double counts; only the next best one is forgone.

Economists say that all societies face scarcity, meaning that—

• a.poor countries lack natural resources
• b.most goods are sold at high prices
• c.wants exceed the resources available✓
• d.money supplies are always shrinking

Scarcity is the gap between unlimited wants and limited resources, and it is why every economy must choose what to produce rather than simply produce everything. High prices are one symptom of scarcity in a particular market, not the definition. The condition applies to rich and poor countries alike, whatever their endowments. And it is about real resources, not about the quantity of money.

A country's gross domestic product measures—

• a.the amount of its currency in circulation at any one time
• b.the value of everything its people own
• c.the value of final goods and services it produces✓
• d.the total savings held by all of its households together

GDP adds up the market value of the final goods and services produced inside a country over a period, which is why it is reported quarterly and annually. Household savings is a stock of accumulated wealth rather than a flow of production. Currency in circulation is a monetary measure. And the total of everything owned is national wealth, a different and much larger quantity.

The unemployment rate counts people who are—

• a.working fewer hours than they would like
• b.enrolled full time in a school program
• c.retired after a long working career
• d.without a job and actively looking for one✓

To be counted as unemployed a person must be jobless and searching, which is why the rate can fall either because people found work or because they gave up looking. Someone working reduced hours is employed, and is captured instead by measures of underemployment. Retirees are outside the labor force. And full-time students who are not seeking work are likewise not in the labor force.

Interest on a loan is best described as—

• a.the amount originally borrowed
• b.the price paid for the use of money✓
• c.insurance against the borrower's death
• d.a tax the lender owes the government

Interest is what a borrower pays a lender for the use of funds over time, and the rate is the price expressed as a percentage. A lender does owe tax on interest received, but the interest itself is not a tax. Insurance on a loan is a separate product with its own premium. And the sum borrowed is the principal, which interest is charged on top of.

A government runs a budget deficit in a year when—

• a.it borrows from foreign lenders
• b.prices rise faster than wages
• c.it spends more than it collects✓
• d.its total debt exceeds its output

A deficit is the annual gap between outlays and revenue, and the accumulated deficits of past years are what make up the debt. Borrowing is how a deficit is financed, so it is a consequence rather than the definition. Debt compared with output is a ratio used to judge the burden, again not the deficit itself. And prices outrunning wages is a statement about real earnings, not about the budget.

A tax is called progressive when—

• a.the rate rises a little every year
• b.every taxpayer pays the same amount
• c.higher incomes pay a larger percentage✓
• d.the money is spent on public works

Progressivity describes how the rate varies with ability to pay: as income rises, the share taken in tax rises with it. A single flat charge on everyone is the most regressive shape there is, since it takes a larger share of a small income. A rate that changes over time is being raised, which says nothing about who bears it. And the use made of the revenue is a separate question from the structure of the tax.

Coffee and tea are substitutes for many buyers. If the price of coffee rises sharply, the likely effect is that—

• a.the supply of tea decreases
• b.the price of tea must be fixed
• c.demand for tea increases✓
• d.demand for tea falls as well

When two goods serve the same purpose, a rise in the price of one sends buyers toward the other, so the demand for tea shifts up. Demand for tea falling with coffee is what you would expect of complements, such as coffee and cream. Nothing about coffee's price changes the conditions under which tea is grown, so tea's supply is unaffected. And no price needs fixing; the market adjusts.

A firm's profit is calculated as—

• a.the price charged for each unit
• b.the value of its buildings and tools
• c.total revenue divided by output
• d.total revenue minus total costs✓

Profit is what remains of receipts after every cost of doing business is paid, which is why a firm with rising sales can still lose money. Revenue divided by output is average revenue, close to the price rather than the profit. The unit price is one input into revenue and says nothing by itself about costs. And buildings and tools are capital assets, a stock the firm holds rather than a flow it earns.

A borrower with a higher credit score can usually expect—

• a.a shorter period to repay the loan
• b.a larger down payment requirement
• c.a guarantee of loan forgiveness
• d.a lower interest rate on a loan✓

A score is a lender's estimate of the risk of not being repaid, and less risk is priced as a lower rate, which is the whole financial value of good credit. A stronger borrower generally faces a smaller down payment, not a larger one. Repayment periods are set by the type of loan rather than by the score. And no score entitles anyone to have a debt cancelled.

A minimum wage law is an example of—

• a.a legal floor under a price✓
• b.a legal ceiling over a price
• c.a subsidy paid to employers
• d.a tax on employing workers

A minimum wage forbids a transaction below a stated price, which makes it a price floor in the market for labor. A ceiling works the other way by forbidding prices above a level, as rent control does. It is not a tax, since no revenue goes to the government. And nothing is paid to employers, who bear the higher wage.

Lines of latitude on a globe—

• a.trace the paths of the major ocean currents
• b.run north and south and converge at the north and south poles
• c.run east and west and measure distance from the equator✓
• d.mark the boundaries between the world's twenty-four time zones

Latitude lines circle the globe parallel to the equator and are numbered by how far north or south of it they lie, which is why they are also called parallels. Lines that run north and south and converge at the poles are meridians of longitude. Time zones are based on longitude rather than latitude. And ocean currents are a physical feature drawn on specialized maps, not a coordinate system.

The equator is the line of—

• a.zero degrees latitude✓
• b.the international date line
• c.the tropic of Capricorn
• d.zero degrees longitude

The equator is latitude zero, the reference circle from which distances north and south are measured, and it divides the Northern from the Southern Hemisphere. Zero degrees longitude is the prime meridian, which runs through Greenwich. The international date line follows roughly the 180th meridian, on the far side of the globe. And the tropic of Capricorn lies about 23.5 degrees south.

Climate differs from weather because climate describes—

• a.the temperature at a single moment
• b.storms that cross a region quickly
• c.conditions expected in the next week
• d.average conditions over many years✓

Climate is the long-run pattern of temperature and precipitation for a place, compiled over decades, which is what lets you pack for a city you have never visited. Next week's conditions are a forecast, the province of weather. A single reading is one observation of weather. And individual storms are weather events, however dramatic.

Urbanization refers to—

• a.people moving between different countries
• b.population shifting from rural areas into cities✓
• c.cities spreading outward into their suburbs and beyond
• d.farmland being divided up into ever smaller plots

Urbanization is the growth of the share of a population living in cities, usually as people leave the countryside for urban work. Cities spreading outward is suburbanization or sprawl, a pattern within urban growth rather than the concept itself. Dividing farmland is a change in land tenure. And movement between countries is international migration, which may or may not end in a city.

In the study of migration, a drought that ruins a region's harvests is—

• a.a chain migration of relatives
• b.a push factor driving people away✓
• c.a pull factor attracting new arrivals
• d.a physical barrier blocking movement

Push factors are conditions in the place of origin that make leaving attractive, and crop failure is a classic example. A pull factor is something in the destination that draws migrants, such as jobs or safety. A barrier is an obstacle in the way, like a mountain range or a closed border. And chain migration describes newcomers following relatives who went before them.

Which ocean lies between the east coast of Africa and the west coast of Australia?

• a.The Indian Ocean✓
• b.The Arctic Ocean
• c.The Atlantic Ocean
• d.The Pacific Ocean

The Indian Ocean fills the basin bounded by eastern Africa, southern Asia and western Australia. The Pacific lies on Australia's other side, to the east. The Atlantic is west of Africa, not east of it. And the Arctic Ocean sits at the top of the globe, far from both coasts.

The Sahara, the world's largest hot desert, lies in—

• a.southern Africa
• b.northern Africa✓
• c.southwestern Asia
• d.central Australia

The Sahara stretches across northern Africa from the Atlantic to the Red Sea, separating the Mediterranean coast from the lands to the south. Central Australia holds its own large arid interior, but not this one. Southwestern Asia contains the Arabian Desert. And southern Africa has the Kalahari and the Namib.

The world's time zones are based on—

• a.ocean basins
• b.lines of latitude
• c.national boundaries
• d.lines of longitude✓

Because the Earth turns on its axis, places at different longitudes meet the Sun at different moments, so the zones are laid out along meridians. Latitude runs the wrong way for this: everywhere on one parallel does not share a clock. Zone boundaries are indeed bent to follow borders for convenience, but the underlying scheme is longitude. And ocean basins have nothing to do with it.

On a topographic map, contour lines are used to show—

• a.elevation above sea level✓
• b.the density of population
• c.the boundaries of counties
• d.yearly rainfall totals

Each contour line joins points of equal elevation, so closely spaced lines mean a steep slope and widely spaced lines mean gentle ground. Rainfall is mapped with its own isolines on a climate map. Population density is normally shown by shading on a thematic map. And county lines are political boundaries drawn on a political map.

A region with large deposits of iron ore and coal close together is most likely to develop—

• a.an export trade in timber
• b.a center of banking
• c.a large fishing fleet
• d.a steelmaking industry✓

Steel is made by smelting iron ore with coke produced from coal, so having both nearby cuts the cost of the heaviest inputs and has drawn steel industries to such places repeatedly. A fishing fleet depends on access to productive waters. Timber exports depend on forests. And banking follows capital, communications and law rather than mineral deposits.

A thematic map shaded to show how many people live per square mile is displaying—

• a.the elevation of the land
• b.birth and death rates
• c.population density✓
• d.total population

Density is a ratio of people to area, which is exactly what people per square mile expresses, and shading is the usual way to show it. Total population is a count that ignores area, better shown by graduated symbols. Birth and death rates describe change over time rather than crowding. And elevation belongs on a topographic or relief map.