能够证明甲烷分子的空间结构为正四面体而不是平面正方形的事实是_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

能够证明甲烷分子的空间结构为正四面体而不是平面正方形的事实是

A．甲烷的4个碳氢键的键能相等

B．甲烷的4个碳氢键的键长相等

C．甲烷的一氯代物只有1种

D．甲烷的二氯代物只有1种

答案

答案：D

如果甲烷是平面正方形结构，则甲烷的二氯代物就有2种，而事实上甲烷的二氯代物只有1种，所以甲烷应该是正四面体形，答案选D。

填空题

阅读下面对话，从方框内的选项中选择恰当的句子完成对话。

A. But I argued with my best friend yesterday.
B. That’s a good idea.
C. I don’t have enough time.
D. What should I do?
E. I’ll try to apologize (道歉) to her.

A: I want to get good grades.    小题1:
B: Maybe you could attend after-school class on weekends.
A:   小题2: I have to do my homework
on weekends.
B: Well, you could ask your friends for help.
A:    小题3:
B: You should say “sorry” to your friend.
A: OK.    小题4:
B: I think you shouldn’t play computer games or watch TV any more.
A:    小题5:   I’ll study harder and harder from now on.
F: The weather! English people are always interested in the weather.

填空题案例分析题

叶肉细胞原生质体的分离和培养的主要过程可以用下面的图解简单表示，根据图解回答问题：

图解中“酶解”所用的酶应该包括（）和（）。