题后面的答案是A 解释中的答案是D。。纠结了。。 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.
我的问题是 D如果是答案 就是说明 habitat 和 population无关 A 如果是答案 就是说明A没有加强结论，只是原文的重写， 但是原文并没有说only，而且所有的有害辐射都给了限定 blocked by atmospheric ozone，所以我觉得也加强了结论啊 求指教。。我觉得A想不明白了。。
Whether UV-B is the only type that can damage genes, it is still true that "Atmospheric ozone blocks UV-B, which can damage genes". A adds neither support nor oppostition to the argument.
D rules out another factor that may contribute to the decline of amphibian population and therefore strengthens the argument.
Whether UV-B is the only type that can damage genes, it is still true that "Atmospheric ozone blocks UV-B, which can damage genes". A adds neither support nor oppostition to the argument.
D rules out another factor that may contribute to the decline of amphibian population and therefore strengthens the argument.
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2011-5-31 09:43:23
收藏
收藏
楼主