问题 填空题

教室里有12盏日光灯,分为4组,由三只开关分别控制,当一只开关闭合或断开时,其中有一组的4盏灯就会同时发光或同时熄灭,而不影响其它各组灯的工作.由此可判断,每组的4盏灯之间是______,而各组灯之间是______.(选填“串联”或“并联”)

答案

由于教室中的电灯的额定电压是相同的,都是220V,要想都正常工作,就必须是并联连接.一个开关可控制四个电灯,说明开关是在这四个电灯的干路上.

故本题答案为:并联;并联.

选择题
阅读理解

We’re all connected. You can send an e-mail message to a friend, and your friend can pass it on to one of his or her friends, and that friend can do the same, continuing the chain. Eventually, your message could reach just about anyone in the world, and it might take only five to seven e-mails for the message to get there.

Scientists recently tested that idea in a study involving 24,000 people. Participants had to try to get a message forwarded to one of 18 randomly(随意地,随机地) chosen people. Each participant started by sending one e-mail to someone they knew. Those who received it could then forward the e-mail once to someone they knew, and so on.

Subjects, who were randomly assigned by researchers from Columbia University in New York, lived in 13 countries. They included an Australian police officer, a Norwegian veterinarian, and a college professor.

Out of 24,000 chains, only 384 reached their goal. The rest petered out, usually because one of the recipients was either too busy to forward the message or thought it was junk mail.

The links that reached their goal made it in an average of 4.05 e-mails. Based on the lengths of the failed chains, the researchers figured out that two strangers could generally make contact in five to seven e-mails.

The most successful chains relied on casual acquaintances rather than close friends. That’s because your close friends know each other while your acquaintances tend to know people you don’t know. The phenomenon, known as the strength of weak ties, explains why people tend to get jobs through people they know casually but aren’t that close to.

So, start networking and instant messaging now. As they say in show business: It’s all about who you know.

小题1:If you want to get into touch with a stranger in the world, how many e-mails might it take for the message to reach him/her?

A.5 to 7

B.18

C.13

D.384小题2:Who does the word “subjects” refer to in the passage?

A.the 384 participants who lived in Australuia

B.the Norwegian veterinarians and college porfessors

C.the 24,000 people randomly assigned by reaearchers

D.the 18 people randomly chosen from 13 countries小题3:What does the phrase “peter out” mean in the fourth paragraph?

A.die out

B.pass away

C.disappear

D.pick out小题4:Why do people tend to get jobs more easily through casual acquaintances than close friends?

A.Because close friends don’t talk with each other so much.

B.Because casual acquaintances can help you know more people and make more friends.

C.Because close friends don’t spend so much time gathering together.

D.Because casual acquaintances are kinder and more willing to help others.小题5: In which part of a newspaper will readers read this passage?

A.Culture

B.Entertainment

C.Information and Technology

D.Health