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无关
E. Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans无关
这题正确选项是B。为什么我觉得是C呢？
原文翻译：L是一种通过鹿的虱子传播给人的一种疾病。一般来看，鹿虱子一般是在幼虫阶段吃了感染的白脚鼠。但是幼虫吃的其它物种就不会感染病菌。如果别的物种增多，那么幼虫吃其他物种变多，所以虱子吃到细菌的机会就会降低。
这道题中原文结论是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.
B选项，如果是yes，则鹿虱子的数量“正”受到鹿虱子幼虫能吃到的食物数量的限制，那么原文结论中增加other species 不一定会减少吃white-footed mice的鹿虱子数量，因此原文结论受到质疑；如果对B选项的回答是no,那么原文结论是成立的。总而言之，对B的不同回答会影响原文结论成立与否。
可能是interpret B 的意思要多想下，比較繞。作者: alannesta 时间: 2011-9-24 06:38
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
选项意思是：在现阶段，鹿虱子的数量是否受到鹿虱子的幼虫能够吃到的食物数量的限制。
如果回答“是”，现阶段确实受到限制，那么即使出现结论中说的“the population of these other species were increased”（增加其它物种数量），鹿虱子也不会因为多吃了其它物种而少吃infected white-footed mice，因为鹿虱子本来就不够东西吃。
鹿蜱虫在幼虫时吃白脚鼠而染细菌，除白脚鼠外还有其他食物不携带细菌，如果这些食物变多，携带细菌的鹿蜱虫数量就会减少。
Whichof the following would it be most important to ascertain in evaluating the argument?
关于B选项的解释：
现在鹿蜱虫的数量有没有受其幼虫阶段的食物供应量的限制。（也就是说幼虫的食物够不够吃）
首先，无论是不是，无菌食物变多都会使带菌食物的比例变小。 如果是：那么即使带菌食物比例小了，还是会被全部吃掉，数量不变，不影响带菌鹿蜱虫的数量。 如果否：那么比例小了就意味着数量也少了，带菌鹿蜱虫就少了。
不知道B选项解释的明不明白，我还有疑问就是D错在哪儿了？如果没有B是不是可以选D？B又比D好在哪儿呢？D.Whether deer ticks that were not infected as larvae can become infected asadults by feeding on deer on which infected deer ticks have fed
未染病的幼虫会不会在成年时由于吃到被染病的鹿蜱虫吃过的鹿肉而染病。
是：结论不成立
否：结论成立
