问题 单项选择题

对麦克斯韦速率分布函数f(v),若速率区间间隔为dv,单位体积内所具有的分子数为n,则表达式nf(v)dv的物理意义是()。

A. 单位体积内速率为v的分子数目

B. 单位体积内分子速率在v→v+dv间隔内的分子数占总分子数的百分比

C.分子速率为v的分子总数

D. 单位体积内,分子速率在v→v+dv区间中的分子数目

答案

参考答案:D

阅读理解

Going Zero Waste means more than dealing with the rubbish we create. It means reducing it, too. People who go Zero Waste are careful about what they do. They never take more than they need, they reuse plastic bags, and they make good plans not to buy more than necessary before going shopping.

Kamikatsu, a Japanese village, has already gone Zero Waste. The 2,000 villagers recycle everything possible. There are 34 different boxes at the recycling center! The villagers sometimes just feel unhappy about what they have to do, but they also see the good side.

Let’s think about how to enjoy a Zero Waste Christmas. By sending recyclable cards, we can help our friends and family reduce(减少) waste. And wouldn’t it be better to enjoy the spirit of Christmas with a real tree that can be re-planted in spring?

Going Zero Waste requires us to think more about what happens before and after we act. It is not always easy. But just think how good it would be, both for ourselves and for the earth we live on, if we never had to waste anything.

小题1:The underlined word “it” in paragraph 1 refer to __________.

A.a plastic bag

B.the rubbish

C.a difficult thing

D.going Zero Waste小题2:Which of the following is a way of going Zero Waste?

A.Plant trees at Christmas.

B.Using plastic bags when shopping.

C.Sending recyclable cards for Christmas.

D.Buying things when you are very hungry.小题3:What is the purpose of this passage?

A.To persuade people to reduce waste.

B.To teach people how to enjoy Christmas.

C.To introduce the life of Japanese villagers.

D.To tell people how to deal with difficulties.小题4:How is the passage developed?

A.Topic--Examples--Discussion

B.Examples--Argument--Topic

C.Topic--explanation--Argument

D.Examples--Explanation--Discussion

填空题