A、 To stay in a very warm room with a lot of people.
B、 To expose oneself to severe weather.
C、 To play outdoors long when it is snowing.
D、 To wait for a bus on a cold and windy day.

【正确答案】 A

【答案解析】解析：从短文中第一段第三句“Colds are caused by viruses harbored in the body…who just may be passing the virus around”可知，待在一个人员聚集又很热的屋子里更易感冒。故选A。

A、 You' ll catch a cold sooner or later.
B、 You've already come down with a cold.
C、 There are viruses hidden in your body.
D、 The room is not warm enough for your health.

【正确答案】 B

【答案解析】解析：从“If you feel a chill when you’re coming down with a cold，you’re already sick”可知，打冷颤代表已经感冒了，故选B。

A、 It is generally believed that colds are caused by exposure to cold weather.
B、 Most colds are "caught" by hand contact.
C、 Cold virus will keep alive for several hours once it leaves human body.
D、 Cold virus can spread around only through the air.

【正确答案】 D

【答案解析】解析：由文章第二段第二句“Numerous studies have now shown that the overwhelming majority of colds are‘caught’by hand contact”可知，空气传播并不是最普遍的感冒传播方式，最普遍的方式是手的接触。故选D。

A、 Wash our hands frequently.
B、 Never rub our nose or eyes.
C、 Throw away tissues immediately after use.
D、 Shake hands with our friends instead of kissing them.

【正确答案】 A

【答案解析】解析：由文章最后一段第二句“Frequent hand washing—on the part of the cold—sufferer as well as other members of the household—will minimize the spread of viruses in this way”可知，勤洗手可以减少感冒病毒的传播机会。故选A。

A、 A cold-sufferer is staying with him in the same room.
B、 The viruses have been exposed to the air for over 3 hours.
C、 He dropped in a warm room.
D、 He shakes hands with a cold-sufferer.

【正确答案】 D

【答案解析】解析：从文章第二段第二句“Numerous studies have now shown that the overwhelming majority of colds are‘caught’by hand contact”可知手的接触是最易发生的感冒传播途径。故选D。