Kate: The recent decline in numbers of theTennessee warbler, a North American songbird that migrates each fall to coffeeplantations in South America, is due to theelimination of the dense tree cover that formerly was a feature of most SouthAmerican coffee plantations. Scott: The population of the spruce budworm, thewarbler's favorite prey in North America, hasbeen dropping. This is a more likelyexplanation of the warbler's decline. Whichof the following, if true, most seriously calls Scott's hypothesis into question? A.The numbers of the Baltimore oriole, a songbird that does not eat budworms butis as dependent on South American coffee plantations as is the Tennesseewarbler, are declining. B.The spruce budworm population has dropped because of a disease that can infectbudworms but not Tennessee warblers.C.The drop in the population of the spruce budworm is expected to be onlytemporary. D.Many Tennessee warblers have begun migrating in the fall to places other than traditionalcoffee plantations.E.Although many North American songbirds have declined in numbers, no otherspecies has experienced as great a decline as has the Tennessee warbler. 答案为A 我选的C 我觉得并没有削弱的意思。不吃budworms的songbird因为咖啡种植园的消失而导致数量的减少，并不能削弱 warbler 可能因为最爱的食物budworm的减少而减少。 哪位能帮忙理清下思路，谢谢！作者: sdcar2010 时间: 2011-2-26 08:07
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.作者: Melodyyang90 时间: 2011-2-26 16:43
明白了，谢谢作者: christete 时间: 2012-5-12 23:06
我怎么想都觉得A有问题啊，A说了另外一种鸟，这就是AA里面的错误类比吗= = 怎么能够削弱S的观点呢。作者: christete 时间: 2012-5-12 23:07
我觉得这题目出的不够严谨。
