试题与答案

试述控制电缆、信号电缆、屏蔽电缆、高频电缆、天线的作用。

题型:问答题 论述题

题目:

试述控制电缆、信号电缆、屏蔽电缆、高频电缆、天线的作用。

答案:

参考答案:

控制电缆:用于负荷控制终端对控制对象的连接,其中包括连接被控开关、检测开关变位情况,以及检测供电线路的电压和电流值。

信号电缆:主要用于对信号的采集,其中包括脉冲电能表脉冲信号的采集和智能电能表485接口信号的采集。

屏蔽电缆:具有抗干扰作用。

高频电缆:用于传送高频信号。

天线:用于接收和发射信号。

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题型:阅读理解

阅读理解。

     Tony is six years old. He is a good boy. But he can't get up early. He sleeps until nine or ten o'clock in

  the morning. He is often late for school.

     Tony's mother doesn't want him to be late for school. So she buys him an alarm clock. She tells Tony,

"you must get up when you hear the clock ring."

     "Yes, Mum,"said Tony. After that Tony get up at seven thirty when he hears the clock ring.

     One day his mother forgets (忘记) to make the clock ring. And the next morning Tony doesn't get up

 at seven thirty. It's time for breakfast. Mother goes to see him. Tony is in bed and his eyes are open.

     "Why don't you get up?" His mother is angry.

      "I am waiting for the bell."

1.Tony's mother buys him a clock, because _____.

    A. he can't get up early in the morning          

    B. the clock is good

   C. Tony likes it                              

    D. she wants to give her son a present

2. This article (文章) is _____.

    A. a piece of news    

    B. a joke        

    C. a letter        

    D. an introduction (介绍)

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