T-9-Q28. 天山-7-13Lyme disease is caused by a bacterium transmittedto humans by deer ticks. Generally deer ticks pick up the bacterium while inthe larval stage from feeding on infected white-footed mice. However, certainother species on which the larvae feed do not harbor the bacterium. Therefore,if the population of these other species were increased, the number of ticksacquiring the bacterium and hence the number of people contracting Lyme diseasewould likely decline.
Which of the following, if true, most strengthensthe argument?
A. Ticks do not suffer any adverse consequences fromcarrying the bacterium that causes Lyme disease in humans.
B. There are no known cases of a human’s contractingLyme disease through contact with white-footed mice.
C. A deer tick feeds only once whilein the larval stage.
D. A single host animal can be the source ofbacterium for many tick larvae.
E. None of the other species on which deertick larvae feed harbor other bacteria that ticks transmit to humans | 
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发表于 2012-11-11 16:06:26
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