一高层建筑设置的湿式系统，喷头现场进行密封性能试验的压力为（）MPa。
A.2
B.3
C.4
D.5
参考答案：B
有资金归集关系的账户要冻结账户时，先冻结账户的（），解冻账户的（），先解冻账户。
A shepherd’s crook is used to（）.
A.lower spring buoys into the water
B.find an anchor after the buoy has been lost
C.transfer a pennant wire to the anchor handling boat
D.clean chain as it is hauled into the rig
