多项选择题：常用的整流电路有（）A、半波整流 B、全波整流 C、桥式整流 D、倍流整流 E、倍压

题型：多项选择题

beep …beep … There went the bell! Robbie opened his eyes. He had been sitting in the room for a whole day, and now it was time for him to do something.

Robbie looked out of the window. It was still snowing heavily and there was ice on the window. It was another cold day. Robbie was told to turn the heat on before the family got home. And he did it.

Then Robbie was told to do some cleaning work at once. It was an easy job for him, but a tough one for his master, Helen. He kept on working until every room was clean and tidy.

For now, he had to cook supper for the family.

The first thing Robbie did was to get the big pot(锅) in the kitchen. Then he put some water in the pot and put it on the stove. He used one of his hands to cut up a chicken and added the pieces to the water to make a good soup. Then he got some tomatoes, cabbages and carrots to make a vegetable salad.

At ten past eight he laid the table. Then he put some bread, the chicken soup and the salad on it. What a sweet smell! The moment he turned on the lights, the whole family came home.

“The soup smells great, Victor,” said Helen. “You really know how to tell Robbie what to do.”

Robbie is one robot that really saves the family a lot of work.

小题1:What is Robbie?

A．A cook.

B．A robot

C．A cleaner

D．A computer小题2:What do the underlined words “did it” in the second paragraph mean?

A．Looked out

B．got home

C．turned the heat on

D．did some cleaning小题3:What time did Robbie lay the table?

小题4:What can we learn from the passage?

A．The story happened on a rainy day.

B．Robbie didn’t have to be told what to do.

C．Helen found it easy to do cleaning work at home.

D．Victor and Helen felt comfortable when they got home.

查看答案

常用的整流电路有（）A、半波整流 B、全波整流 C、桥式整流 D、倍流整流 E、倍压

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