A.20r/minB.80r/minC.120r/minD.160r/min
A.斷線故障B.低電阻接地故障C.高電阻接地故障D.無故障
A.斷線故障B.斷線故障低電阻接地故障C.高電阻接地故障D.高電阻接地故障無故障