逻辑一道JJ求解！！！大神们求解释~~~~~~~~

花露水6

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 whitefooted 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.

还是不懂B为什么不对：这里是想减少人的患病率 那么人可能因为很多原因患病吧 被鹿传染就是一种 但是也有可能被MICE传染 所以现在说减少传染的鹿能够减少患病 那么我们得排除不会被MICE传染，排除他因不对吗？



如果被infected的鹿减少，而还有更多的mice能传染人，那么被传染的人还是会增多啊。


求解释啊~~~~~~~~~~~~~~

云游

Nahh...you've just overassumed here...don't waste time on reading the conclusion. It says the number of ticks acquiring the bacterium and hence the number of people contracting Lyme disease—would likely decline.

There are two elements in the conclusion.

zizibaobao11141

只是no known 并不代表真的没有啊

-唯唯豆奶-

题目给了三个条件，1.Lyme疾病来自于跳蚤。2.幼虫期食用感染的白鼠的跳蚤才携带病毒。3.幼虫期食用其他食物的跳蚤不携带病毒
题目由此得出的结论是：增加吃别的食物的跳蚤种类就可以减少L疾病的患者

题目问加强，通过寂静中给出的逻辑链可以清楚的得出这题加强的关键就是排除他因，shadow已经给出了很好的YY，“即：传染L疾病的幼虫除了白老鼠，就不吃其他的东西了，其他种类的跳蚤亦然（即它们除了自己的食物不会去吃白鼠）。”这样一来，很容易就直接选定C。
你提到了选项B，B的错误在于irrelevant。老鼠是否会直接传染人类这一点我们通过题目不得而知。

希望解答了你的疑惑。

花露水6

-唯唯豆奶- 发表于 2013-7-22 23:31
题目给了三个条件，1.Lyme疾病来自于跳蚤。2.幼虫期食用感染的白鼠的跳蚤才携带病毒。3.幼虫期食用其他食物 ...

可是题干中并没说Lyme disease is only caused by a bacterium transmitted to humans by deer ticks.