在一封闭容器中，理想气体的算术平均速率提高一倍，则（）。 A_爱下问搜题

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问题单项选择题

在一封闭容器中，理想气体的算术平均速率提高一倍，则（）。

A．温度为原来的1/4，压强为原来的4倍

B．温度为原来的4倍，压强为原来的1/4

C．温度和压强都提高为原来的1/4

D．温度和压强都提高为原来的4倍

答案

参考答案：D

解析：

根据算术平均速率可知，当平均速率提高一倍时，温度提高为原来的4倍；再根据理想气体状态方程p=nkT可知，压强也提高为原来的4倍。

阅读理解

A
Xia Ming was worried about his study, so he wrote a letter to a magazine.

Dear editors,
I’m a slow student in my class. Most of my classmates are much better than me. So I get very stressed out. It’s difficult to keep on working hard and it’s really not fun. And I think although I spend much time studying for the tests. I can’t get good grades. My father gives me some help sometimes. He tells me not to worry about it. But what do you think I should do?
Xia Ming

Two readers read the letter from the magazine and here are their answers:

Dear Xia Ming,
Many famous people are not so good at the age like you. Edison, the famous scientist, had a bad headache for his studies when he was a 12-year-old boy. But everyone knows that he did a lot for the people in the world. And Newton had the same story like him. You should take it easy, then try your best. I believe you can do better.
Thumbelina

Dear Xia Ming,
When you are feeling stressed out, just smile and take a deep breath(深呼吸), you should believe tomorrow is another day.
Mr Unsmart

小题1:Xia Ming worried about ______.

A．his classmates

小题2:Thumbelina gave ______ examples in the letter.

小题3:Thumbelina wrote about those famous people _______.

A．to make Xia Ming feel better

B．to make Xia Ming laugh

C．to show how much she knows

D．to show that she dislike them

小题4:Which is NOT true?

A．Xia Ming doesn’t have fun studying at school.

B．Xia Ming’s father always helps him with his study.

C．Smiling can reduce the pressure.

D．Edison is famous in the world.

小题5:“Tomorrow is another day.” tells us ______.

A．it’s the weekend tomorrow

B．Xia Ming can get good grades tomorrow

C．tomorrow is different from today

D．there are hopes in our lives

单项选择题

含铬丰富的食物不包括（）。

A.肉类

B.鱼贝类

C.精制谷物

D.啤酒酵母

E.动物肝脏