下列各组物理量中，都不随取水量的变化而变化的是……（）

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问题选择题

A．水的沸点、蒸发水所需的热量

B．水的密度、水中通入足量二氧化碳后溶液的pH

C．水的体积、电解水所消耗的电量

D．水的物质的量、水的摩尔质量

答案

答案：B

A-D中，水的沸点、水的密度、水中通入足量二氧化碳后溶液的pH、水的摩尔质量不随取水量的变化而变化。其余均与水量成正比。

单项选择题

When I was looking for a Christmas present for my daughter in a toy store, a nicely dressed little girl, with some money in her little hand, was looking at some beautiful dolls. When she saw a doll she liked, she would ask her father if she had enough money. He usually said yes.
At the same time, a boy, with old and small clothes, was looking at some video games. He, too, had money in his hand, but it looked no more than five dollars. Each time he picked up one of the video games and looked at his father, he shook his head.
The little girl had chosen her doll, a very beautiful one. However, she noticed the boy and his father. She saw the boy give up a video game with disappointment and walk to another corner of the store.
The little girl put her doll back to the shelf and ran over to the video game. After she talked to her father, she paid for the video game and whispered(耳语) to the shop assistant.
So the boy got the video game that he wanted for free—he was told it was a prize from the store. He smiled happily, although he felt it was so incredible. The girl saw all this happen. She smiled, too.
When I walked out of the store to my car, I heard the father ask his daughter why she had done that. I would never forget their short talk. " Daddy, didn’t Grandma want me to buy something that would make me happy"
He said, "Of course, she did. "
"Well, I just did!" With that, the little girl started skipping towards their car happily.

The story happened in a ______.

A．school

B．toy store
C．cinema

D．computer room

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单项选择题

以下与表面活性剂有关的参数是

A．置换价
B．Krafft Point
C．顶裂
D．临界相对湿度
E．F_o

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