单项选择题
A.电压B.电能质量C.电流D.频率
A.AB.BC.CD.D
A.150%,0.1sB.150%,0.5sC.120%,0.1sD.120%,0.5s
A.20s到5minB.20s到1minC.15s到1minD.10s到1min
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