问题 单项选择题

关于集成运放的下列说法,正确的是()。

A.输出电阻很大

B.输入电阻很小

C.工作时不需要外接直流电源

D.用于线性运算时,一定要采用闭环的形式

答案

参考答案:D

阅读理解

阅读理解。

    Prana was a beautiful dog, whose name means "breath of life". Although he died several years ago, I can

still remember the days we spent together and what he has taught me about love.

    I have two apple trees in the garden. Prana loved apples. When he went outside, he'd catch an apple and

take it into the house to eat later. The apples had been on the ground and were often dirty so I wasn't always

happy that Prana had brought them into the house.

    It was an autumn day in America, but it was very cold. A big snow fell and we had not done anything for

its coming. On that special day, Prana went outside and I watched him through the window. I noticed that he

was madly digging (挖) holes and bringing the apples to the ground so they could be seen above the snow. I

did not know why he was doing this. He seemed to want to do something special.

    When I called him back, he had his usual one apple in his mouth. About five minutes later, I looked outside.

The garden was completely covered with birds. Prana had dug up all those apples for his bird friends to eat.

He knew that they wouldn't have stored enough food for the coming winter!

1. Prana was            . [ ]

A. the writer

B. a boy

C. a bird

D. a dog

2. I wasn't always happy because            . [ ]

A. Prana loved apples

B. Prana caught an apple and ate it

C. the apples fell on the ground and were dirty

D. Prana brought the dirty apples into the house

3. On the snowy day, Prana            . [ ]

A. ate up all the apples

B. dug holes to put the apples in them

C. brought the apples under the snow to the ground

D. left the house and died

4. The birds flew to the garden to            . [ ]

A. look for Prana

B. eat the apples

C. make new homes

D. store food for the winter

5. The topic of the story is about            . [ ]

A. apples

B. animals

C. love

D. life

判断题