RRU电源线屏蔽层接地,若电缆长度超过()米,需在电缆中间部分加做一处防雷接地。
A.80
B.70
C.60
D.50
参考答案:B
_______ many times , he still couldn’t understand it.
A.Told
B.Having been told
C.He was told
D.Though he had been told
灭火救援业务训练手段有()。
A、利用现有器材装备训练
B、利用建(构)筑物训练
C、利用模拟设施器材训练
D、利用预案训练
E、利用电教设备教学训练