单项选择题
A.hoist man
B.limit switch
C.brake handle
D.preventer bar
单项选择题 After launching,an inflatable raft should be kept dry inside by().
单项选择题 After jacking down your liftboat you have an unexpected list.You find that the only cause of this list must be a flooded leg.Your next course of action should be to().
单项选择题 After being rescued from the vessel accident,the people agreed that they had much to().