狒狒38

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.
   （这题明明是A）

(B) Amphibian populations are declining far more rapidly than are the populations of nonamphibian 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.

后面答案是A，详解答案是D；

个人认为，应该是A，D为排除他因的加强，即派出因栖息地减少而使两栖动物减少这个他因；

另外，文中结论是ozone layer减少导致amphibian declining，没有提UV-B。

即使有其他radiation同样有害，但因为缺少ozone layer，同样能导致amphibian decline，因此强调UV-B的唯一性不能strengthen.

不只理解对否，sorry for any duplication.