系统运行中出现于设备绝缘上的过电压一般有( )。
A．空载过电压 B．雷电过电压 C．操作过电压 D．谐振过电压
参考答案：B,C,D
Look, Grace just takes after the man. I think he be her father.
A. must B. can C. can’t
