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问题 多选题

下列各组元素，即能形成共价化合物，又能形成离子化合物的是（　　）

A．Ne、Mg、Ag

B．H、Ag、S

C．Ca、H、Cl

D．N、H、Cl

答案

A、Ne属于稀有气体元素，化学性质稳定，不能形成共价化合物、离子化合物，故选项错误．

B、Ag的金属活动性较弱，不能形成离子化合物，故选项错误．

C、Ca、H、Cl可以形成离子化合物氯化钙，又可以形成共价化合物氯化氢，故选项正确．

D、N、H、O可以形成离子化合物氯化铵，又可以形成共价化合物氯化氢，故选项正确．

故选CD．

单项选择题 A1型题

以下何脉不主宿食()

A.紧脉

B.促脉

C.滑脉

D.结脉

E.涩脉
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阅读理解

Many teenagers feel that the most important people in their lives are their friends. They believe that their family members, and in particular their parents, don’t know them as well as their friends do. In families, it is quite often brothers and sisters to fight with each other and then they can only go to their friends for advice.

It is very important for teenagers to have one good friend or a circle of friends. Even when they are not with their friends, they usually spend a lot of time talking among themselves on the phone. This communication is very important in children’s growing up, because friends can discuss something difficult to say to their family members. However, parents often try to choose their children’s friends for them. Some parents may even stop their children from meeting their good friends. The question of “choice” is an interesting one. Have you ever thought of the following questions?

Who chooses your friends? Do you choose your friends or your friends choose you?

小题1:Many teenagers think their _____ know them better than their parents do.

A．friends

B．teachers

C．brothers and sisters

D．family members小题2:Which of the following is right according to the passage?

A．Parents should like everything their children enjoy.

B．In all families children can choose everything they like.

C．Parents should try their best to understand their children better.

D．Teenagers can only go to their friends for help.小题3:Which is the best title for this passage?

A．Only Parents Can Decide

B．Parents and Children

C．Teenagers Need Friends

D．A strange Question
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