问题 问答题 简答题

使用钳型电流表进行测量时,应注意什么?

答案

参考答案:

应注意以下事项。

(1)根据被测电流回路的电压等级选测合适的钳型电流表,操作时要防止构成相间短路。

(2)使用钳型电流表前,先应注意选择合适的测量档位,使其指针正确指示,不能使指针过头或指示过小。

(3)要保持安全距离,不得造成相间短路或接地,烧坏设备或危及人身安全。

(4)测量时铁芯钳口要紧密闭合,被测导线尽量置于孔中心,以减小测量误差。

阅读理解

阅读理解。

     I came to study in the United States a year ago. Yet, I did not know the real American society until I was

injured in a car accident because after the car accident I had to see a doctor-and go to court (法庭).

     After the accident, my roommate called a doctor for me. I was very grateful and determined to repay him

one day. But the next day, he asked me to pay him $200 for what he had done. I was astonished. He had good

reason to charge me, he said. And if I wanted to collect money from the person who was responsible for my

injury, I'd have to have a good lawyer. And only a good doctor can help me get a good lawyer. Now that he

had help me find a good doctor, it was only fair that I should pay him.

     But every time I want to see doctor, I had to wait about 50 minutes. He would see two or three patients at

the same time, and often stop treating one so as to see another. Yet he charged me $115 each time. The final

examination report consisted of ten lines and it cost me $215.

     My lawyer was all smiles the first time we met. But after that he avoided seeing me at all. He knew very

well the other party was responsible for the accident, yet he hardly did anything. He simply waited to collect

his money. He was so irresponsible that I decided to dismiss him. And he made me pay him $770.

     Now I had to act as my own lawyer. Due to my inexperience, I told the insurance (保险) company the date

I was leaving American. Knowing that, they played for time and I left without getting a cent.

     My experience taught me two things about America: firstly, in a country like America money is everything.

It is more important than friendship, honor or professional morality (道德). Secondly, foreigners are still being

treated unfairly. So when we talk about America, we should see both its good and bad sides.

1. The author's roommate offered to help him because _____. [ ]

A. he felt sorry for the author

B. he thought it was a chance to make some money

C. he knew the doctor was a very good one

D. he wanted the author to have a good lawyer

2. A good doctor is essential for the author to _____. [ ]

A. to be properly treated

B. talk with the person responsible for the accident

C. recover before he leave America

D. eventually get the responsible party to pay for his injury

3. Both the doctor and the lawyer in the passage are very _____. [ ]

A. friendly

B. greedy

C. professional

D. busy

4. What conclusion can you draw from the story? [ ]

A. Going to court is something very common in America.

B. One must very careful while driving a car.

C. There are more bad sides in America than good sides.

D. Money is more important than other things in America.

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