通常有（）方式启动EPIRB
A.1
B.2
C.3
D.都对
参考答案：B
A．(A) Sometimes nothing at all.
B．(B) A sandwich and a cup of coffee.
C．(C) Some vitamin pills.
D．(D) Some mineral water.
锚喷支护锚杆必须进行抗拔力试验，检验频率判定要求？
