FeiFei-38

D排除一种他因，假如Amphibian住的地方越来越少的话，其数量也就越来越少。

A的UV-B是不是唯一一种对基因有伤害的对结论没影响，结论是臭氧的减少导致了Amphibian的减少。

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.

(D) The natural habitat of amphibians has not become smaller over the past century.

because Atmospheric ozone blocks UV-B, if atmospheric has been depleted, UV-B will harm genes. so I think that A support the conclusion,but is not unrelated with the conclusion.

把老贴翻出来, 费费宝典详解中的答案错了. 正确答案应为A.

文章并没有说一定是damage gene才导致decling population. 只不过在描述UVB是, 一笔带过它有这个性质. 关键在于amphibians身上没有protection "they are particularly vulnerable to UVB radiation".

建议斑斑改详解中的答案, 要不confused.