问题 选择题
如图所示为一磁流体发电机示意图,A、B是平行正对的金属板,等离子体(电离的气体,由自由电子和阳离子构成,整体呈电中性)从左侧进入,在t时间内有n个自由电子落在B板上,则关于R中的电流大小及方向判断正确的是(  )

A.I= ,从上向下

B.I= ,从上向下

C.I= ,从下向上

D.I= ,从下向上

答案

答案:A

阅读理解

阅读理解。

     Mr. and Mrs.Turner live outside a small town.They have a big farm and they are always busy working on it. Their son, Peter, studied at a middle school. The young man studied hard and did well in his lessons. It made them happy.

     Last month Peter finished middle school and passed the entrance examination (升学考试).Mrs.Turner was very happy and told the farmers about it.

     Yesterday morning the woman went to the town to buy something for her son. On the bus she told one of her friends how clever and able her son was. She spoke very loudly. All the people in the bus began to

listen to her.

     "Which university (大学) will your son study in?" a woman next to her asked.

     "In the most famous university in our country!" Mrs. Turner said happily.

     "The most famous university?""Oxford University (牛津)."

     Most of the passengers (乘客) looked at her carefully. Some of them said to her, "Congratulations!"

A woman said, "I'm sure he'll know Fred Smith.""Who's Fred Smith?""He's my son." "Does he study in

the university, too?" "No, "said the woman. "He is one of the professors."

l. The story happened in _______.

A. America

B. France

C. Germany

D. England

2. Mr. and Mrs. Turner were happy because _______.

A. their son did well in his lessons

B. they have a big farm

C. they have a good harvest

D. their son studied at a middle school

3. Mrs. Turner wanted everyone to know _______.

A. her son finished middle school

B. her son was handsome

C. her son was going to study in a university

D. her son was very friendly to others

4. Mrs. Turner spoke so loudly in the bus that _______.

A. her friend could hear her

B. all the people could hear her

C. she hoped to make all the people happy

D. she hoped they would say congratulations to her

5. Which of the following is true? _______.

A. The woman wasn't interested in Mrs. Turner's words

B. Mrs. Turner knew nothing about the famous university

C. The woman wanted to stop Mrs. Turner from showing off (炫耀)

D. The woman next to Mrs. Turner wanted to show off her son, too

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