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问题 单项选择题 共用题干题

某大鱼塘周围，建有各种工厂，最近居民常反映食用该鱼塘的鱼有煤油味。

引起鱼体“煤油味”的成分可能是（）。

A.铁

B.挥发酚类

C.锰

D.锌

E.铜

答案

参考答案：B

多项选择题

在图中M点位于两层予应力锚杆之间，下列选项中( )说法是错误的。

A．M点土压力随着施工进行总是增加的

B．M点土压力随着施工进行总是减小的

C．M点土压力不随着施工过程而变化

D．M点土压力随着施工进行而动态变化
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单项选择题

People often recall having felt chilled before the onset of a cold. This supports the hypothesis that colds are, at least sometimes, caused by becoming chilled; it is the chill that allows a rhino virus, if present, to infect a person. Which of the following, if true, most seriously weakens the force of the evidence cited above

A．Being chilled is a form of stress, and stress lowers the defenses of a person’s immune system, which guards against infection.

B．After a rhino virus has incubated in a person for several days, the first symptom it causes is a feeling of chilliness.

C．People who are tired and then become chilled are more likely to catch severe colds than are people who are chilled without being tired.

D．Some people who catch colds are not sure what it was that allowed them to catch cold.

E．(E) Rhino viruses are not always present in the environment, and so a person could become chilled without catching a cold.
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