38. Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth’s ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulnerable to UV-B radiation. In addition, their gelatinous eggs lack the protection of leathery or hard shells. Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.
Each of the following, if true, would strengthen the argument EXCEPT:
A. Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes. B. Amphibian populations are declining far more rapidly than are the populations of non-amphibian species whose tissues and eggs have more natural protection from UV-B. C. Atmospheric ozone has been significantly depleted above all the areas of the world in which amphibian populations are declining. D. The natural habitat of amphibians has not become smaller over the past century. E. Amphibian populations have declined continuously for the last 50 years.
答案：D 思路：原文论述臭氧层的破坏造成UV-B辐射过量是导致两栖动物数量减少的主要原因。 A：支持说明为什么是UV-B而不是其他原因。 B：支持说明为什么UV-B会降低两栖动物的数量。 C：提供空间论据说明臭氧层受损和两栖动物数量减少的相关性。 D：中性评价。不Weaken也不Strengthen. E：提供时间论据说明臭氧层受损和两栖动物数量减少的相关性。作者: sdcar2010 时间: 2012-3-1 10:53
A is right.作者: 子弹青春 时间: 2012-3-2 09:36
I think D is the right answer, because I can not find a reason to support the argument from D.作者: 小吉要加油 时间: 2012-3-2 10:40
我选的也是A 感觉D又提到了另一个影响因素，没什么直接作用作者: sdcar2010 时间: 2012-3-2 10:58
The natural habitat of amphibians has not become smaller over the past century.
D) removed another possible reason to explain the phenoma of decreasing population. Thus, it is a strengthener since it is more likely what the author says is correct.作者: snowfish88 时间: 2012-3-2 12:01
谢谢各位大牛，先回复再看作者: snowfish88 时间: 2012-3-2 12:04
所以答案是A，网上通用的答案D为错？作者: Beilo 时间: 2012-4-12 15:34
答案应该是A吧？！D实际上是排除他因，就是说数量减少不是由栖息地减少造成的，从而加强了论点吧……作者: katy2230 时间: 2017-12-11 15:50
同意！ 作者: kluivert 时间: 2018-9-16 15:12
D典型的加强型的 ... 排除他因就是对结论的支持
A不相关 ，对结论产生不了任何影响 作者: klmadge 时间: 2020-9-5 11:53
这题正确答案应该是A，700-800最后那套super 100里面也有这道题目，附上曼哈顿给的解析：
This question is much more difficult than the previous question, in part because one of the wrong answer choices is very attractive.
The conclusion of the argument is a causal statement that the depletion of the ozone layer is the primary cause of the declining amphibian population:
DO = depletion of the ozone layer, DA = decline of amphibian population, DO -> DA.
This conclusion is based on the fact that the ozone layer blocks harmful UV-B radiation, which amphibians are vulnerable to in both adult and egg form. Although the argument mentions UV-B radiation, which may sound impressive, the structure of the reasoning is easy to follow and no knowledge of the radiation is needed. The conclusion is clearly stated and easy to spot due to the indicator “thus.” The question stem is a StrengthenX and therefore the four incorrect answers will each strengthen the argument. As with the previous question, look for answers that fit the five causal strengthening answer types discussed earlier.
Answer choice (A): This is the correct answer. The answer fails to shed any light—positive or negative—on the connection between the ozone depletion and the amphibian population decline. Because the argument is concerned with the damage done by UV-B radiation, the fact that UV-B is the only damaging type of radiation blocked by ozone is irrelevant.
Answer choice (B): This answer choice strengthens the argument by showing that when the cause is absent in non-amphibian populations, the effect does not occur (Type C).
Answer choice (C): This answer strengthens the argument by showing that the areas of ozone depletion and amphibian decline match each other, thereby affirming the data used to make the conclusion (Type E).
Answer choice (D): This was the answer most frequently chosen by test takers. This answer choice strengthens the argument by eliminating an alternate cause for the effect (Type A). Had the natural habitat become smaller over the years (from say, human encroachment or climatic change) then that shrinkage would have offered an alternate explanation for the decline in the amphibian population. By eliminating the possibility of habitat shrinkage, the stated cause in the argument is strengthened.
Answer choice (E): This answer strengthens the argument by showing that the decline of the amphibians has mirrored the decline of the ozone layer, thereby affirming the data used to make the conclusion (Type E).
