问题 选择题

三个完全相同的杯子中均装满水,将用细线拴好的质量相同的铜块、铁块和铝块(已知ρ>ρ>ρ)分别慢慢浸没在三个杯子的水中,然后再提出水面,此时三个杯子中所剩水的水面比较(  )

A.放铁块的水面高

B.放铜块的水面高

C.放铝块的水面高

D.三个杯子中水面一样高

答案

由密度公式ρ=

m
V
可知,质量相等的不同物体,密度大的体积小,

∵ρ>ρ>ρ

∴V<V<V

∴铜块排开水的体积最少,溢出的水体积最小,剩余水的水面较高.

故选B.

填空题
阅读理解

阅读理解。

Dear Sir or Madam,

  When I first came to Shenzhen, the first thing that surprised me most was the

newspaper. We can see people reading newspapers everywhere, on the bus or on

the street. Newspapers play an important part in China. Reporters who get their

news first will have the market and win.

  I myself like reading newspapers very much, both in English and in Chinese,

as readers, we enjoy being in a sea of news every day, But few of us are sure

about the importance of the reporters, who help people when they are in trouble.

We get much closer to the world because of them. They are the pioneers! And I

love brave reporters, who must be the greatest people in the world. For their

readers, sometimes they are in danger; each year a certain number of reporters

die for their jobs all over the world. I feel so sad for that. With China's entry into

the WTO, reporters will play a more important part.

                                                                                                 Sincerely yours,

                                                                                                          Lee

1. The writer is interested in        .

A. reading reports

B. reading newspapers

C. watching people in the street

D. watching reports

2. The writer wants to say that        are very important.

A. newspapers      

B. readers      

C. reporters

D. people

3. By reading newspapers, we         the world.

A. nearer 

B. know more  about

C. close    

D. open

4. In the writer's opinion, the reporters are         .

A. great        

B. pioneers        

C. brave        

D. all the above

5. Why does the writer feel sad?

A. Few people read newspapers today.

B. Few people know the reporters' im0ortance.

C. Some reporters are in danger now.

D. Some reporters diet for their jobs.