[求助]新 prep2 100 版主牛牛快来。。

angelwds

100.
    (30745-!-item-!-188;#058&005748)     (T-9-Q28. ��ɽ-7-13 , different type)

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

这道题的答案是B，想问一下，B的意思是不是说

现在deer ticks的数量是被幼年时期的deer ticks的可食用的数量所限制？

如果是，那么加强

如果否，那么种群数量增多，还会有很多鹿去吃白脚老鼠，所以感染的数量更多了？

[此贴子已经被作者于2009/8/8 19:20:27编辑过]

sophiaruan

不是。题目的意思是人通过鹿虱感染，鹿虱幼虫期通过老鼠感染。有些别的物种不会感染，如果不感染物种多了，那么大部分的病毒会在不感染的物种上寄生，那么鹿虱感染的数量就少了。

B的意思是带有鹿虱幼虫期的动物可用性是否限制了鹿虱的数量？如果限制了，那么会感染的鹿虱就少了，没有限制，鹿虱的数量就不会减少。

angelwds

以下是引用sophiaruan在2009/8/7 19:07:00的发言：

不是。题目的意思是人通过鹿虱感染，鹿虱幼虫期通过老鼠感染。有些别的物种不会感染，如果不感染物种多了，那么大部分的病毒会在不感染的物种上寄生，那么鹿虱感染的数量就少了。

B的意思是带有鹿虱幼虫期的动物可用性是否限制了鹿虱的数量？如果限制了，那么会感染的鹿虱就少了，没有限制，鹿虱的数量就不会减少。

看来题目的理解有偏差，我试着翻译一下我的理解

Lyme disease is caused by a bacterium transmitted to humans by deer ticks. 

Lyme病的发生是因为细菌从deer ticks身上传染到了人的身上

Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. 

一般情况下，deer ticks在幼年时期吃了感染的white-footed mice而获得细菌

 However, certain other species on which the larvae feed do not harbor the bacterium.

但是，一些特定的物种（幼年时期的鹿所捕食的）  并不藏匿细菌

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.

如果这些特定物种的数量增加，更多的幼鹿将持这些不感染的物种，因此获得细菌的幼鹿的数量就会下降

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

是否现在deer ticks的数量是被幼年时期的deer ticks的可食用（得到）的动物的数量所限制

ruoshany

我觉得LZ翻译没问题, 但B对是因为: 题中问的是to evaluate the argument..也就是它的有效性. if deer ticks are not limited by the availability of those animals, then its ineffective to increase the the population of other species, since they can still choose to feed on the infected white-footed mice. on the other hand, if the size of the deer ticks population is limited by that, then the increase in the population of other animals will result in that deer ticks have to feed on the increase part of other species,leading to the decrease in the number of ticks acquiring the bacterium..

angelwds

哦~ LS的意思是说，

如果deer ticks确实是被幼年时期的所吃的动物所限制，那么他就只能吃那些不会感染的物种

如果deer ticks没有被被幼年时期的所吃的动物所限制，那么他依旧可以吃到白脚老鼠，所以不会decrease

ruoshany

对,就是这个意思