GWD-6-Q13:恳请大家帮忙,谢谢

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 from feeding on infected white-footed mice.  However, certain other species on which the larvae feed do not harbor the bacterium.  Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium―and hence the number of people contracting Lyme disease—would likely decline.

Which of the following, if true, most strengthens the argument?

A.   Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.

B.   There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.

C.   A deer tick feeds only once while in the larval stage.

D.   A single host animal can be the source of bacteria for many tick larvae.

E.   None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans.

   Answer: C

这道题 实在想不通为什么是C,恳请大家帮忙

L病是由鹿的虱子携带给人的一种细菌造成的。一般鹿的虱子在幼虫的阶段携带了细菌当他们在吃white-footed mice东西的时候。而幼虫在吃其它食物的时候是没有细菌携带的。因此如果其它的食物来源增加，则其带菌的虱子的数量就会下降。

问加强

A显然和结论没关系

B说L病和什么whitemice没关系，也和结论没什么关系，

C虱子在幼虫的时候只进食一次－－－如果就吃一次，那么如果其它不带菌的食物增加，则幼虫带菌的几率就减小

D宿主是细菌的来源，没什么意义，虱子就只在吃white mice的时候带细菌

E提到其它细菌，不属于文章讨论范围