采用小接地的厂用电系统发生单相接地时，借助（），可以知道哪一_爱下问搜题

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问题单项选择题

采用小接地的厂用电系统发生单相接地时，借助（），可以知道哪一相发生了单相接地。

A、绝缘监察电压表

B、厂用电电源的电流表

C、厂用电电源的有功表

答案

参考答案：A

完形填空

The young engineer sat down on a rock and rested his head in his hands. He would never get home; it was   36  . For weeks he had been   37 in the Northwest Canadian forest. Now there was a terrible   38  behind his eyes, and   39  of all, he had gone blind.
Suddenly a man 40 out of the woods, an Indian who had been hunting in the area. Seeing the engineer's 41  , he caught a fish in a nearby   42  and fed the sick man the 43  of the fish and some flesh from its head. 44  within a few hours the engineer's pain was   45  . A day later he could 46 again, and the next day he had 47 recovered.
When he returned home, the engineer told the 48  to Dr Price.   49  years later did it become a(n)   50 fact that this was just an everyday lifeguard doing its work. For what the engineer did, by eating fish eyes, was to   51 vitamin (维生素).
Vitamin A's biggest job is to keep the eyes   52 . Without Vitamin A, people and animals get night blindness and other eye problems. Without Vitamin A, people can even be totally blind. Vitamin A helps to keep the skin in good   53 . A also helps 54 bones and teeth and has something to do with proper   55  of blood cells.

B．Immediately

C．Fortunately

D．Surprisingly

D．disappeared

名词解释

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