标题: 求助一道逻辑题。 [打印本页] 作者: sumproduct 时间: 2012-12-5 11:00 标题: 求助一道逻辑题。 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 white-footed 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?
Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice. A deer tick feeds only once while in the larval stage. A single host animal can be the source of bacteria for many tick larvae. None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans.作者: Believer6 时间: 2012-12-5 12:45
选第二个对么？ 如果正确的话是因为第二个选项排除了它因。也就是说排除了人类感染的其他途径。个人意见，不知道对不对。作者: sumproduct 时间: 2012-12-6 10:57
答案是C~~作者: walt77 时间: 2012-12-6 11:11
莱姆病是由一种细菌引起的 这种细菌由鹿蜱在人类身上传播。通常来说，鹿蜱 在其幼虫阶段通过吸收感染这种细菌的white-footed 老鼠 来携带。然而，鹿蜱幼虫 吸收的其他种类 没有 这样的细菌。因此，如果这些其他种类的 数量上升，那么，有细菌的鹿蜱的数量 及 感染莱姆病的人的 数量 很可能会 下降。 问加强 一只鹿蜱 在幼虫阶段 只吸食一次。