( )不属于电力系统内部的过电压。
A.感应雷击引起的过电压 B.操作过电压C.谐振过电压 D.雷电波侵入引起的过电压
参考答案:A,D
It’s difficult ___ that we shouldn’t spend all our time ______ our favorite hobby.
A.to remember, in
B.to remember, on
C.remember, in
D.remembering, on
试分析直接染料轧染初开车时,为何需要对染液进行况水冲淡?