单项选择题
A.瓷绝缘子B.环氧树脂绝缘子C.母线绝缘子D.低压绝缘
A.0.70m B.0.30m C.0.35m D.0.50m
A.不超过200mm B.不超过50mm C.不超过100mm D.不超过150mm