在一次初三学生数学交流会上，每两名学生握手一次，统计共握手253次．若设参加此会

阅读理解。

     Now, China has the second largest number of Internet users in the world after the United States. Many

of Chinese Internet users are teenagers. They spend about 13 hours every week online. On the Internet,

students can find out almost anything. Surfing the Internet can help them with their homework and learn a

lot of knowledge.

     People can use the Internet to write letters, stories and to send emails. Many teenagers keep in touch with

their friends online. They can also make new friends through QQ or ICQ. Some of the students surf the

Internet just for fun. They like to listen to music, watch films, and go to their favorite stars' websites.

     But some parents always think that the Internet takes young people away from study."They spend too

much time playing computer games and most games are about killing and fighting. It's too dangerous.

And there are some dirty things on the Internet," says the mother of a 13-year-old boy.

1. According to this passage, China has the ________ highest number of Internet users.

A. second

B. third

C. first

D. fourth

2. Some of the students surf the Internet for fun. What can they do?

A. They can listen to music and watch films.

B. They can go to their favorite stars' websites.

C. They write letters stories and send emails.

D. A and B.

3. Some parents worry that the Internet is ________.

A. helpful

B. dangerous

C. traditional

D. useful

4. The phrase ''keep in touch with" means ________.

A. 保持联系

B. 交朋友

C. 打电话

D. 写信

5. What's the best title (题目) of this article?

A. The Internet

B. The Computer

C. The Teenagers

D. The Mother

一定质量的理想气体在A状态的内能一定大于B状态的内能的图线是（　　）

A．

B．

C．

D．

若(AX)=0122H，四个标志位CF、SF、ZF、OF的初始状态为0，执行指令SUB AX, 0FFFH后，这四个标志位的状态是______。

A) (CF)=O，(SF)=0，(ZF)=0，(OF)=0
B) (CF)=1， (SF)=1， (ZF)=0， (OF)=0
C) (CF)=0， (SF)=0， (ZF)=1， (OF)=1
D) (CF)=1， (SF)=1， (ZF)=1， (OF)=1

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