对可更换的低压断路器的灭弧触头，如磨损厚度为原来的（）时要考虑更换。
A.1/3
B.1/4
C.1/5
D.1/6
参考答案：A
在一定的时间内，电流通过导体某一横截面的电量越多，电流就______．电流的大小用______表示，简称______．
In “My purpose is to help you feel less stressed .” “to help you feel less stressed” is used as .
A．subject
B．predicative
C．object
D．attributive
