标题: GWD3-Q38 C选项错在哪里？ [打印本页] 作者: chenxuleon 时间: 2010-11-13 00:02 标题: GWD3-Q38 C选项错在哪里？ GWD3-Q38: Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of the dense tree cover that formerly was a feature of most South American coffee plantations. Scott: The population of the spruce budworm, the warbler’s favorite prey in North America, has been dropping. This is a more likely explanation of the warbler’s decline. Which of the following, if true, most seriously calls Scott’s hypothesis into question? A. The numbers of the Baltimore oriole, a songbird that dose not eat budworms but is as dependent on South American coffee plantations as is the Tennessee warbler, are declining. B. The spruce-budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers. C. The drop in the population of the spruce budworm is expected to be only temporary. D. Many Tennessee warbler have begun migrating in the fall to places other than traditional coffee plantations. E. Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler.
而A是: 另一种鸟oriole不吃budworm但依靠South American coffee plantations也减少了，等于将coffee plantation和oriole连上，而oriole的栖息特性和warbler一样，也等于将coffee plantation和warbler连上，刚好跟Scott的论点相反。 作者: sdcar2010 时间: 2010-11-13 00:26
In weakening type questions, you use information from the answer choices to provide counter evidence against the stated conclusion. You do not need to kill the original argument. Neither can you use outside information beyond what is stated in the stimulus and the answer choices.
Answer (A) is a direct attack on Scott's idea that budworms are the source of the problem because answer (A) provides an example that a species that doesn't eat budworms (or, to put it another way, is not affected by the cause of change proposed by Scott) also experienced exactly the same decline. Therefore, answer (A) adds more credibility to Kate's theory and, at the same, casts more doubts on Scott's hypothesis.
When you say 而A在逻辑上存在的漏洞也是很明显的，有可能是他因造成A选项中的那种鸟的减少, you are ADDING more information to the question. This is not allowed in logic reasoning.作者: chenxuleon 时间: 2010-11-13 14:19
楼上2位说的都在理，谢谢了，J'ai mieux compris, merci！