Reading comp PrepTest 146 · Section 4 · Question 24

Correct. Question Type:
Strengthen

Strategy Overview:
Find the section discussing the long-term effects of CFCs as predicted by Molina and Rowland, then find an answer that backs it up

Answer Anticipation/Relevant Lines:
We've learned that predictions about the future are important on the LSAT—they show up quite a bit in LR questions. So we should have noted the prediction ("long-term effects") made here.

Checking our notes, we see that a prediction was made at the beginning of Paragraph 3. There, Molina and Rowlands predict that, even if CFC production and use stopped immediately, the depletion of the ozone layer would continue for years or decades (Lines 36-41). So let's find an answer that suggests that they're right about the long-term effects here.

Answer Explanation:
(Lines 36-41; Lines 51-53) The hole in the ozone layer was proof that Rowlands and Molina were right about the effects of CFCs on the ozone layer, and they predicted that even if their use was immediately stopped, the ozone layer would continue to be depleted over years/decades. This answer states that the hole in the ozone layer which proved them right continued to grow even after the use of CFCs stopped, matching their prediction. As such, this answer strengthens their argument about the long-term effects of CFCs, making it the correct answer.

Key Takeaway:
Predictions are important in LR—we even categorize many conclusions as predictions, and we generally think about things that could change between the present and future that would prevent them from coming to pass. In RC, be sure that you note predictions so that you can quickly find them when they show up in the questions—and they likely will show up there.

Incorrect. (Lines 21-24) Rowlands and Molina's observations already established that CFCs diffused upwards, so what happens with other chemicals is out of scope of their argument about the long-term effects of this specific class of chemicals.

Incorrect. (Lines 31-33) The passage notes that chlorine destroys a lot of ozone before becoming inactive, but it doesn't discuss a timeline over which that happens—it could be a few hours! As such, this answer doesn't speak to the long-term effects. Maybe if it said something about the length of time that chlorine reacts compared to other chemicals!

Incorrect. There are three issues with this answer. First, other scientists getting on board doesn't mean that they were right! Second, this answer is about "many" of the scientists who were initially against them—maybe even more are still against them, or maybe some of their supporters turned! Finally, this answer is about the soundness of their methods, not their conclusions or predictions. For these two reasons, this answer doesn't

Incorrect. (Lines 39-41) M&R's prediction was about the continued depletion of the ozone layer even if everyone stopped using CFCs. If countries are still using CFCs, then it's hard to know if any current depletion is due to the newly released CFCs or the existing CFCs in the atmosphere. This answer muddies the waters, which definitely doesn't strengthen the argument.