单选题 People faint (晕) when the normal blood supply to the brain is suddenly cut down. This can happen if they are surprised or shocked by sudden news or by something they see. Some people faint if they see others hurt. Some people faint in crowds. Others faint if they are in a room that is hot and with all the windows closed.
If a person faints while standing, lay him down. If his face is pale, lift his feet. If he is sitting down when he faints, place his head between his knees. Loosen any tight clothing that might keep him from breathing easily. If possible, place cold, wet cloth on his forehead.

单选题 The passage says that people may faint if they are______.
A. worded B. frightened C. happy D. worded and frightened

【正确答案】 B

【答案解析】在原文第1段第2句话指出人们在受到惊吓时会晕倒。因此选项B．frightened是正确答案。

单选题 If you feel faint when you are standing, it is best to______.
A. run about B. stand up C. lie flat D. move slowly

【正确答案】 C

【答案解析】原文第2段第1句话指出如果一个人站着感到晕了，让他躺平。因此选项C．lie flat是正确答案。

单选题 If you feel faint when sitting, put your head______.
A. to one side B. on your chest C. against the chair back D. between your knees

【正确答案】 D

【答案解析】在原文第2段第3句活指出当一个人坐着感到晕了，把头放在膝盖中间。因此选项D．between your knees是正确答案。

单选题 Raise a fainting person's feet if his face______.
A. looks pale B. feels hot C. shows shock D. both B and C

【正确答案】 A

【答案解析】原文第2段第2句话指出当一个人的脸色发白时把晕倒的人的双脚提高。因此选项A．looks pale是正确答案。

单选题 We try to help a person who has fainted by______.
A. rubbing his head B. returning blood to his brain
C. tightening his muscles D. holding him in an upright (垂直) position

【正确答案】 B

【答案解析】原文第1段第1句话指出人们晕倒是因为脑供血突然中断，所以去帮助一个晕倒的人就要帮助把血液回到大脑中。因此选项B．returning blood to his brain是正确答案。