问题 单项选择题

当存在外部不经济时,市场决定的产量将会( )。

A.等于社会理想产量

B.大于社会理想产量

C.小于社会理想产量

D.都有可能

答案

参考答案:B

解析: 当存在外部不经济时,说明某个人进行某项活动对他人产生了不利的影响,而自己却不会得到惩罚,因此这个人实施这项活动时付出的私人成本小于社会成本,所以这个人显然会采取这项活动,尽管从社会的角度看,该活动是不利的。一般而言,存在外部不经济的情况下,私人活动的水平常常要高于社会所要求的最优水平,即市场决定的产量大于社会理想产量。

阅读理解

阅读理解。

     What are your clothes made of? Are they made of cotton or wool? Some students in Shandong

wear different things. Their clothes are made of discs (光盘) or old clothes!

     On October 7th, 36 students in Linyi, Shandong Province, wore beautiful clothes in a show. Their

clothes were made of all kinds of things.

     The show gave the students a chance to make things with their own hands. It also helped them learn

to make good use of waste and not to throw everything away.

      Students had lots of good ideas. Some found used things, like old clothes, to make new dresses.

      "We hope to save energy. Our world is short of energy. So I don't want to just throw old things

away," said Xie Jing at Linyi Art School.

      Xie had more than 20 discs on her nice blue dress. She got them from her family and friends.

      "Though the discs are old, I look very cool in them!" she said.

      Song Dandan, a student from the school, looked like a farmer in her straw (稻草) coat and hat. She

picked the straw from the fields and put them all together.

       "I want to show what people wore in the past." she said.

       Du Yue made clothes for astronauts (宇航员)! She had white cloth all over her. When she walked,

she tried to be slow. It looked like she was walking on the moon.

      "I hope to wear it in space (太空) some day. I wish that I could walk on the moon!" she said.

1. The passage mainly talks about ____. 

A. how to make clothes

B. energy saving

C. how to look cool

D. a special fashion show

2. The students' clothes were made of ____. 

A. silk

B. cotton

C. waste paper

D. all kinds of things

3. The underlined (画线) word "short" in the sentence "Our world is short of energy. " has 

    the same meaning as "short" in the sentence "____"

A. It's only a short way from here. 

B. The man is short. 

C. I'm short of money. Can you lend me some?

D. She was here a short time ago.  The show tells people ____.

A. we should save energyB. they are clever

C. how to make use of old thingsD. A, B and C

4. The three students used all these things except ____ to made clothes. 

A. discs

B. straw

C. old paper

D. cloth

5. The show tells people ____. 

A. we should save energy

B. they are clever

C. how to make use of old things

D. A, B and C

问答题 简答题