单项选择题
A.每千伏1WM B.每千伏0.5WM C.每千伏0.2WM D.每千伏0.02WM
A.大轴上安装接地炭刷 B.加强大轴绝缘 C.轴承座牢固接地 D.加强轴承座绝缘
A.15S和60S B.15S和45S C.20S和70S D.20S和60S