请教一题

stoneren

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 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.

答案是A。想不通。

Cherryfavour

确认答案A
思路：将A取非，得到：还有其它射线会破坏基因，再加上原题的前提，得到臭氧层破坏越严重，破坏基因的射线种类和数量越多，导致A动物的数量减少越快，起到加强作用。
取非后加强，所以本身是消弱。

stoneren

zt 卧室春竹：

我觉得 38 关键说的是 Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer. 就是ozone得消失..

UV-B这个东西是不是唯一损害GENES无所谓吧！

关键看结论... 加强总的加强结论吧？！