- UID
- 1355931
- 在线时间
- 小时
- 注册时间
- 2018-8-12
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
Which of the following most logically completes the argument?
Lyme disease is caused by a bacterium transmitted to people by deer ticks. Deer ticks are almost never born infected with the bacterium, but they can pick it up from feeding on an infected host in any of the tick's three successive stages of development: larva, nymph, adult. Once infected, a tick remains infected through any subsequent developmental stages, but since a tick feeds on only one host in each stage, it follows that __________.
A people can be infected only by being bitten by a tick that is either in the larval stage or in the nymph stage
B people cannot be infected by a tick that picked up the Lyme disease bacterium in the adult stage
C it is not possible for a person to be infected by a tick that is in the nymph stage or by a tick that was infected with the bacterium while in the nymph stage
D people infected with the Lyme disease bacterium cannot transmit the bacterium to adult deer ticks
E only deer ticks that are adults can transmit the Lyme disease bacterium to people
正确答案: B
我自己的理解如下，但是做题时觉得每个答案都不对....
F: 莱姆病是由DT接触时细菌传播引起的；DT只有在出生后卵/幼虫/成年三阶段因为吃了感染的宿主而被传染上； 一旦感染，终身感染。
P: 每个阶段只吃一只宿主
C: ？
|
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2019-3-24 23:07:02
收藏
收藏
