Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline. Which of the following would it be most important to ascertain in evaluating the argument? A. Whether populations of the other species on which deer tick larvae feed are found only in areas also inhabited by white-footed mice B. Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on C. Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice D. Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed E. Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans -- by 会员 kevinno007 (2010/8/10 19:34:38)
转过来的解释，希望对你有帮助
其实该题单纯从有关无关就可以找到答案C
原文推理是：1。T传细菌给人类，人类感染L病。2。T在幼虫是吃M就带该细菌。3。幼虫吃其它东西不带该细菌。所以（结论），其他东西多拉，携带该细菌的T就少，人类感染L病的机会也少。
A。无关。T携带该细菌是否有反作用和结论无关
B。无关。主要有两个因素决定和结论无关。1是原文讨论的是T传细菌给人类导致人类得L病，人类直接接触M 是否得L病与原文无关。2是知不知道有没有这样的CASE并不代表实际有没有，所以对原文不起作用。
C。支持。T 在幼虫期只是进吃一次。既然只吃一次，这次不是吃M就是吃其他东西，当其他东西变多时，吃M的机率就变少，所以T感染该细菌就少。支持结论
DE都无关。 | 
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发表于 2010-8-11 08:35:42
