A.低后備 B.高后備 C.母差 D.速斷
A.普通電纜交流電纜 B.普通電纜直流電纜 C.阻燃電纜交流電纜 D.阻燃電纜直流電纜
A.1%,0.5% B.0.5%,0.5% C.0.5%,1% D.1%,1%