问天山7－13

huoni

新手上路，多多指教～

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

这题到底应该选什么啊？我怎么觉得一个都不对啊，不太明白那个species到底是指tick还是mice～

huashengke

我觉得应该选b，对其取否，如果人能直接被white-footed mice传染，那么不管other species增加或者减少，人感染该病的人数就不会下降。

aprilJR

我也觉得选B,B排除了contact with white-footed mice的可能性，应该是加强阿，怎么答案选C?

3bao

答案是C

A deer tick feeds only once while in the larval stage

当他在larval stage只吃一次饭时，other species数量增多，他才有可能吃到other species

如果他吃很多顿饭就不一定吃什么了，哈哈，饥不择食就是这个道理~~