下列说法正确的是（） A．物质的量可以理解为物质的质量 B_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

下列说法正确的是（）

A．物质的量可以理解为物质的质量

B．物质的量就是物质的粒子数目

C．物质的量是量度物质所含微观粒子多少的一个物理量

D．物质的量的单位——摩尔只适用于分子、原子和离子

答案

答案：C

题目分析：物质的量是度量物质所含微观粒子多少的一个物理量，其单位是摩尔。物质的量只能用于微观粒子，例如分子、原子、电子、离子等。所以只有选项C是正确的，其余都是错误的，答案选C。

点评：本题非常简单基础。

补全对话，情景问答

根据对话内容及方框中所给的句子补全对话。选项中有一项是多余的。

A. Work must come first.
B. I'll talk with your parents about the problem.
C. My parents like me to play basketball.
D. What's wrong with you?
E. The problem is that I love basketball.
F. I have a problem.

A: Hello, Uncle John!
B: Hello, Bob! 1._____ You look worried and upset.
A: 2._____ I really need your help.
B: What do you mean?
A: Well, 3._____ But now it becomes more and more difficult since I am in Grade Nine. My parents don't
allow me to play basketball.
B: Maybe your parents are right. 4._____
A: I see. I do well in all my lessons and I think I should be allowed to do the things that I'm interested in.
B: OK. 5._____
A: Thank you, Uncle John. It's very nice of you.

问答题简答题

主电路采用了哪些保护装置？