{请教}new prep100 谢谢！

bonfin

100.(30745-!-item-!-188;#058&005748)
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

看了几遍都无法理解为什么选B，请各位解释一下·~~~~~~~~~~~~~~谢谢！！！！！！！！！！！！

bonfin

我看了一个小时都没有理解。。。有人么。。。

bonfin

5个ticks, 2个mice  那么这5个可以同时寄生在mice上面，最后5个都有传染病。
如果加了B限制，假设一个mice上只能有一个trick，那么最多只有2个tricks可以去选mice，其他的就必须找另外的宿主，而增加的宿主只有无病毒的动物，所以最后就是只有2个受感染

应该是这样~~

小我less

貌似懂了 谢谢~~

cherrylmy

............

qianxueyoufei

bonfin 发表于 2011-10-18 19:25
5个ticks, 2个mice  那么这5个可以同时寄生在mice上面，最后5个都有传染病。如果加了B限制，假设一个m ...

为什么D不对呢