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标题: 求助啊 [打印本页]

作者: 二丫zheng    时间: 2011-6-26 21:07
标题: 求助啊


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

题目是看懂了,但就是看不懂正确选项的意思,也想不出个所以然来?谁来解释一下 啊







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