避雷器的作用是什么?
参考答案:
避雷器是用来限制过电压,保护电气设备的绝缘免受雷电和操作过电压的危害
It is well known that Germany’s car industry is ______ its beer.
A.as a symbol much as
B.as much a symbol as
C.so much the symbol as
D.so the symbol much as
蹩压法是怎样进行井下泵况诊断的?