求問pp3_100

wojiaodubing

答案是B我選D

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

tofreesky

我觉得答案B是正确的。

虱子可以寄生在白蹄老鼠和其他种类老鼠上，白蹄老鼠带细菌，其他种类不带，得出结论，增加其他种类老鼠，这样虱子寄生在其他老鼠上，就会相对减少带细菌的可能性。

如果其他老鼠增加了，虱子也相对的多了，那么还是会寄生到白蹄子老鼠上。所以需要评价一下现在的虱子数量是不是太多，就是像B说的那样

sunnybyy

还有另一个版本的题目：

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.

OA is C

ashleych

D 无关， out

instinctwu

楼上兄台解释的很好！
D选项说deer ticks feed on dear!!!这个概念在文中从来就没提过，无关项
我倒是在E选项上踌躇了很久，后来想明白了
即使E的事情发生了，但是这些bacteria是否会导致infection，也是不确定的，所以E也无关了