Drill 3 · Reading & Writing · Hard Command of Evidence
SAT Reading & Writing: Hard Command of Evidence (Drill 3) is a Reading & Writing practice drill covering Hard Command of Evidence. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.
Five hard Command of Evidence questions covering new findings, a graph, a table, and a scholarly quotation. The tempting wrong answers are true or close, but only one does the exact job the claim requires. Read the data items carefully and check each quotation against the precise assertion it is meant to back.
Cells lining the gut release a signaling molecule that tells the body it has eaten. Researchers noticed that these cells make large amounts of a particular surface protein, and that the molecule is released only from the cell surface. They concluded that this protein is the channel through which the molecule leaves the cell, proposing that the molecule passes out through the protein itself. They based the conclusion on the protein's abundance and its location on the surface.
Question 1. Which finding, if true, would most directly weaken the researchers' conclusion?
Explanation: Choice B is the best answer because the conclusion is that the molecule leaves through this protein, so a finding that cells making none of the protein still release the molecule normally shows the protein is not needed for export and is likely not the channel. Choice A is wrong because the protein appearing on other gut cells does not address whether it is the export route in these cells. Choice C is wrong because the molecule's size next to other channels never tests whether this particular protein carries it. Choice D is wrong because how long the protein takes to reach the surface leaves the export route entirely unsettled.
Stone Artifacts by Excavation Layer (deeper layers are older)
| Layer | Finished tools | Waste flakes |
|---|---|---|
| 1 (most recent) | 120 | 240 |
| 2 | 90 | 270 |
| 3 | 60 | 300 |
| 4 (oldest) | 80 | 120 |
Archaeologists expected that the ratio of finished tools to waste flakes would fall steadily in older layers, since older toolmakers were thought to finish fewer tools on site. The ratio does fall from Layer 1 through Layer 3. The team was surprised to find that the trend did not continue, noting that the oldest layer, Layer 4, instead ________
Question 2. Which choice most effectively uses data from the table to complete the statement?
Explanation: Choice D is the best answer because the surprise is that the oldest layer breaks the falling trend. Layer 4 has 80 tools to 120 flakes, a ratio of about 0.67, which is higher than Layer 3's 60 to 300, or 0.20, and higher than Layer 2's as well, so the ratio rises again in the oldest layer instead of continuing to fall. Choice A is wrong because Layer 4 actually has the fewest waste flakes at 120, not the most, so this misreads the table. Choice B is wrong because Layer 3 has the fewest finished tools at 60, not Layer 4, so this is a misreading. Choice C is wrong because the ratio does not keep falling; Layer 4's ratio is higher than Layer 3's, which is the whole surprise.
On coral reefs, small cleaner fish pick tiny parasites off the bodies of much larger fish, which hold still and allow it. Biologists proposed that this is a mutually beneficial partnership, with the large fish gaining real health benefits rather than merely tolerating the cleaners. They wanted evidence that the cleaning does the large fish concrete good, not just that the interaction occurs.
Question 3. Which finding, if true, would most directly support the biologists' proposal?
Explanation: Choice A is the best answer because the proposal is that the large fish gain a real health benefit, so the evidence must link cleaning to better health. Large fish losing access to cleaners developing more parasite-caused sores than those that keep cleaners shows the cleaning concretely protects their health. Choice B is wrong because where cleaner fish station themselves shows the interaction happens but not that it benefits the large fish. Choice C is wrong because large fish lining up shows they seek cleaning but not that it does them concrete good. Choice D is wrong because the cleaners' coloring helps them be recognized but says nothing about a health benefit to the large fish.
A clinic tested whether switching appointment reminders from email to text messages would raise the share of patients who actually attend. It sent email reminders to half its patients and text reminders to the other half, and measured attendance within three age bands. The clinic concluded that text reminders help mainly its youngest patients, reasoning that the move from email to text should lift attendance most where people rely on their phones the most.
Question 4. Which choice best describes data from the graph that support the clinic's conclusion?
Explanation: Choice C is the best answer because the conclusion is that texts help mainly the youngest patients, which is a claim about where the email-to-text gap is largest. The graph shows a large gap in the 18 to 34 band, about 61 versus 83, but nearly equal bars in the 35 to 54 and 55-plus bands, so the benefit is concentrated in the youngest group. Choice A is wrong because a higher text bar in the youngest band alone is true but does not show the benefit is concentrated there rather than shared across ages. Choice B is wrong because the highest text attendance being in the youngest band describes one series and ignores the email comparison the conclusion needs. Choice D is wrong because where email attendance peaks is about the wrong series and does not speak to the text-versus-email gap by age.
The early-twentieth-century muralist Elena Doran painted large public works in train stations and markets, using flat blocks of color and simplified figures rather than the fine detail of gallery painting. In an essay, a student asserts that Doran simplified her style specifically so that ordinary passersby, not trained art audiences, could read her murals at a glance.
Question 5. Which quotation from a scholarly article best supports the student's assertion?
Explanation: Choice A is the best answer because the assertion is specifically that Doran simplified her style so ordinary passersby could read the murals quickly. The keyed quotation ties the flattening and loss of detail to making meaning register on a moving crowd that never stops, which matches both the stylistic choice and the goal of quick public legibility. Choice B is wrong because praise from gallery critics speaks to her reception among trained audiences, the opposite of the ordinary-passerby point. Choice C is wrong because the number of murals she made is a biographical fact that does not address why she simplified her style. Choice D is wrong because this gives the same stylistic choice but attributes it to her own dislike of fussy detail, not to helping passersby read the work, so it matches the style but not the stated purpose.