采用单点起吊匀质细长杆件时,吊点的位置拟在距离起吊端的()L(L为杆的长度)。
A.0.1
B.0.2
C.0.3
D.0.5
参考答案:C
AIDS control and prevention is a to China as well as the whole world. [ ]
A. surprise
B. challenge
C. reaction
D. threat
电机车采用的二种消弧方法是()。
A、电磁吹弧消弧
B、消弧降温消弧
C、气体消弧