ACT English: Topic Development (Drill 2)

Question 1. The writer is considering deleting the underlined sentence. Should it be kept or deleted?

• A) Kept, because it gives specific detail that supports the opening claim about historical mystery. ✓
• B) Kept, because it introduces the topic of early sailing for later discussion.
• C) Deleted, because the paragraph is about modern ocean technology, not historical limitations, as the paragraph presents the topic.
• D) Deleted, because information about early sailors is covered in a previous paragraph.

Explanation: Choice A is correct. The paragraph is built on a before-and-after contrast: the ocean was once a total mystery, but modern technology has unlocked it. The underlined sentence is the specific evidence that makes the "historical mystery" claim concrete, without instruments, without knowledge of deep-sea creatures, the ocean floor truly was unknowable. It directly supports the opening sentence and sets up the "Today" contrast in the final sentence. Without it, the paragraph jumps abruptly from the vague claim of mystery to modern discoveries. Choice B gives a wrong reason, sailing is not a topic developed later; it serves this paragraph. Choice C argues the paragraph is only about modern technology, but the contrast with the past is essential to the paragraph's structure. Choice D invents a prior mention that does not exist in this excerpt.

Question 2. The writer wants to add a sentence at [A] that provides specific evidence for the opening claim. Which choice best accomplishes this goal?

• A) Many teenagers report staying up past midnight on school nights.
• B) Studies show that adolescents who sleep fewer than eight hours perform significantly worse on memory and attention tests than peers who get adequate rest. ✓
• C) Some high schools now offer optional study halls during first period for students who arrive tired.
• D) The American Academy of Pediatrics was founded in 1930 and represents over 67,000 pediatricians.

Explanation: Choice B is correct. The opening sentence claims sleep deprivation has "measurable effects on the teenage brain." The word "measurable" is the key; it signals that the next sentence should provide a concrete, quantifiable finding. Choice B delivers: fewer than eight hours of sleep leads to significantly worse memory and attention test scores. This is specific, research-based, and directly proves that the effects are measurable. Choice A describes a behavior (staying up late) rather than a brain effect; it tells us the problem exists but does not demonstrate the measurable cognitive impact. Choice C describes a school response (study halls), which belongs after the evidence, not in place of it. Choice D provides background on a medical organization, interesting context but not evidence of sleep deprivation's cognitive effects.

Question 3. The writer is considering deleting the underlined sentence. Should it be kept or deleted?

• A) Kept, because it provides helpful context about the Colorado River's importance.
• B) Kept, because it explains why the river had to be diverted in the first place.
• C) Deleted, because the paragraph focuses on the engineering process, not the river's geography or history. ✓
• D) Deleted, because the Colorado River does not actually empty into the Gulf of California.

Explanation: Choice C is correct. The paragraph narrates a specific engineering sequence: divert the river (tunnels) → dry the riverbed → pour the foundation. The underlined sentence interrupts this sequence to discuss where the river ends up geographically and its historical importance to indigenous communities. Neither piece of information connects to the construction process being described. The paragraph's logic flows perfectly from sentence 2 (tunnels to redirect the river) to sentence 4 (dry riverbed allows foundation work), the underlined sentence adds nothing and breaks the flow. Choice A argues the context is helpful, but helpful to a different essay, not this paragraph. Choice B claims the sentence explains why diversion was needed; it does not; it discusses geography and history, not engineering necessity. Choice D invokes factual accuracy, which is never the right reason to delete on the ACT.

Question 4. The writer is considering deleting the underlined sentence. Should it be kept or deleted?

• A) Kept, because it establishes the paragraph's central claim and frames the details that follow. ✓
• B) Kept, because the passage contains an extended discussion of honey production later on.
• C) Deleted, because the paragraph already explains pollination without needing an introductory claim.
• D) Deleted, because the sentence about honey is not relevant to a paragraph about pollination.

Explanation: Choice A is correct. The underlined sentence is the paragraph's topic sentence; it introduces the main claim (bees are essential to plant reproduction) and sets up the mechanism described in sentences 2 and 3 (pollen transfer) and the consequence stated in sentence 4 (food crop dependency). Without it, the paragraph would open with "As a bee visits a flower..." which plunges into a process without orienting the reader. The mention of honey in the topic sentence is not off-topic; it creates a contrast that sharpens the claim: bees are known for honey, but that's not their most important role. Choice B misreads the passage, honey production is not discussed later. Choice C argues the paragraph doesn't need the introductory claim, but a paragraph of process details needs a topic sentence to give those details meaning. Choice D misidentifies the honey reference as a distraction rather than a contrast device.

Question 5. The writer wants to add a sentence at [A] that strengthens the argument that libraries serve an essential function for underserved communities. Which choice best accomplishes this goal?

• A) The first public library in the United States opened in Peterborough, New Hampshire, in 1833.
• B) Many libraries also host author readings and book clubs that attract avid readers.
• C) In a recent national survey, sixty-four percent of library visitors reported that library services were unavailable to them anywhere else in their community. ✓
• D) Library budgets are typically funded through a combination of local taxes and state grants.

Explanation: Choice C is correct. The paragraph argues that libraries serve an essential function specifically for underserved communities, people who cannot access these services elsewhere. Choice C directly supports this with survey data showing that nearly two-thirds of library visitors could not get these services anywhere else. This is precisely the kind of evidence that makes the "lifeline" argument in the closing sentence compelling. Choice A provides historical background (first public library in 1833), interesting, but irrelevant to the argument about underserved communities today. Choice B mentions author readings and book clubs, these serve avid readers, not the underserved communities the paragraph is focused on. Choice D explains library funding mechanisms, related to the institution broadly but provides no evidence about the communities that depend on libraries.