韶山3B型电力机车吊杆上部用()和构架上的电机悬挂吊座相连。
A.螺钉
B.销
C.捐栓
D.键
参考答案:B
— was the weather there yesterday?
— It was hot and humid.
交联聚乙烯多芯电力电缆的最小弯曲半径不得小于电缆外径()倍。
A.5
B.10
C.15
D.20