讨论：NEW PREP CR2-100

小娟子NUNU

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? D
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

这个题的答案是B，不理解。我选了D，但是好像觉得D有点小不对。请各位大侠走过路过指点下。谢谢！

captain_mas

我的理解是，B选项——如果 the size of the deer tick population没有被deer幼年可捕食的动物的availability限制的话，那么结论就是不成立的。

小娟子NUNU

Thanks for your reply.

bettytons

The conclusion of the argument is:
if the population of these other species were increased, the number of ticks

acquiring the bacterium would likely decline.

you have to stick to this conclusion, though. Anything that does not have to do

with the CONNECTION between INCREASING THE POPULATION OF OTHER HOST SPECIES and the

number of infected ticks ... is irrelevant.