jade3 wrote:
The importance of the ozone layer to terrestrial animals is that it entirely filters out some wavelengths of light but lets others through. Holes in the ozone layer and the dangers associated with these holes are well documented. However, one danger that has not been given sufficient attention is that these holes could lead to severe eye damage for animals of many species.
Which one of the following is most strongly supported by the statements above, if they are true?
(A) All wavelengths of sunlight that can cause eye damage are filtered out by the ozone layer where it is intact.
(B) Few species of animals live on a part of the earth’s surface that is not threatened by holes in the ozone layer.
(C) Some species of animals have eyes that will not suffer any damage when exposed to unfiltered sunlight.
(D) A single wavelength of sunlight can cause severe damage to the eyes of most species of animals.
(E) Some wavelengths of sunlight that cause eye damage are more likely to reach the earth’s surface where there are holes in the ozone layer than where there are not.
OFFICIAL EXPLANATION:
When reading the stimulus, your eye should be drawn to the modifier and indicator words, which are underlined below: The scope of the stimulus is relatively broad, and aside from the word “entirely,” most of the modifiers are not absolute. Now, look at the rest of the problem and see how several of the answer choices attempt to prey upon those who did not read the stimulus closely. Here are the question stem and corresponding answer choices for the stimulus above: With the previous discussion in mind, let us analyze the
answer choices:
Answer choice (A): The very first word—“all”—should be a red flag. Nowhere in the stimulus do we have support for stating that all damaging wavelengths are filtered out by the ozone layer. The stimulus only states that the ozone layer filters “some” wavelengths and lets others through. Some of those that are filtered are dangerous, as indicated by the last sentence. Surprisingly, about 10% of all test takers select this answer choice.
Answer choice (B): We know that many animal species could suffer severe eye damage, and from this we can infer that some of them live in areas threatened by the ozone layer. We do not know that few of the species live in non- threatened areas. Do not forget the Fact Test—it will eliminate any answer choice without support.
Answer choice (C): Nothing in the passage proves this answer choice. If you selected this answer thinking that “many” implied “not all,” then you made a simple, correctable mistake. “Many” can include “all.”
Answer choice (D): Again, watch those modifiers! One reason the answer choice is incorrect is because it references “most” species when the stimulus only discusses “many” species.
Answer choice (E): This is the correct answer. We can follow the chain of connections in the stimulus to prove this answer: the ozone layer filters some wavelengths of light; holes in the ozone layer are dangerous, but one previously overlooked danger of the holes is possible eye damage for many species. From these two statements we can infer that the holes must be letting some damaging wavelengths of light through. This is essentially what answer choice (E) states.
The lesson from this question is simple: read closely and pay strict attention to the modifiers used by the author. Even though you must read quickly, the test makers expect you to know exactly what was said, and they will include answer choices specifically designed to test whether you understood the details.
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