问题 填空题

(8分) 现有下列晶体, 请按要求回答相应问题。(前六个小题用编号填空)

A.干冰

B.晶体硅

C.氩

D.二氧化硅 E.氯化铵(1)通过非极性键形成的晶体是      

(2)属于非电解质且熔化时只需破坏分子间作用力的是      

(3)属于分子晶体,且分子为直线型结构的是       

(4)不含任何化学键的晶体是   

(5)固态时不导电,熔融状态下能导电的是       

(6)含有离子键、共价键、配位键的化合物是     

(7)已知石墨在一定条件下可将D还原成B,反应方程式为SiO2+2C======Si+2CO,若石墨中C—C的键能为a,SiO2中Si—O的键能为b,晶体硅中Si—Si的键能为c,CO的键能为d,请用a、b、c、d表示生成晶体硅时的反应热△H=                   

答案

单项选择题
阅读理解

阅读理解。

     A new research shows that in Britain more and more people are returning to the old tradition that the whole

family have a meal at table. Worrying about the obesity and breakdown of a family, people change their eating

habits so greatly, according to analysis. They find the number of the family having a meal together increases by

5% from 2002 to 2004, and most people who have meals with their family come from the rich social class.

     The new discovery makes doctors and the people struggling against obesity extremely excited. Giving up the

tradition that the whole family have a meal together is exactly one of the reasons for a series of problems

including children's overweight. If a child has a meal in front of the television or the computer alone, he will

often eat some fast food.

     Jason Collins is one of the persons returning to the old tradition. Collins is a manager of a bake (烘面包)

house. He finds after he gets used to having a meal at home with his child, the child becomes much more

obedient (听话的). Dr. Jin is a child psychologist, and she expresses welcome to this result of the study. She

says it can make parents have a very good chance to chat with the child when the whole family have a meal

together.

1. What makes people change their eating habit back to the old tradition in Britain? [ ]

A. Worrying about their children.

B. Worrying about some social problems.

C. Worrying about the living expense.

D. Worrying about health and family problems.

2. We can infer from the passage that _____. [ ]

A. people's eating habit has much effect on their family

B. most rich people have meals with their family

C. most children have the problem of overweight

D. most children don't like having dinner with the parents

3. How do the people who hope to lose weight feel about the new discovery?[ ]

A. They feel glad.

B. They feel surprised.

C. They feel sorry.

D. They feel disappointed.

4. Which of the following statements is TRUE according to the passage? [ ]

A. The child having dinner with his parents doesn't like watching TV.

B. Children become overweight all because of having dinner alone.

C. The family having dinner together is more united and friendly.

D. The reason a child has dinner alone is that he likes fast food.