单项选择题 After the boat is at the top of the davit heads，the davit arms begin moving up the tracks and are stopped by the（）.

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（）.