单项选择题
A.Locked up
B.Readily accessible for use
C.Inaccessible to passengers
D.On the topmost deck of the vessel at all times
单项选择题 You have been towing astern and have just let go the tow.Your deckhands are pulling in and faking the towline by hand on the stern.The most dangerous action to take is to（）.
单项选择题 You are operating a lift boat.When beginning to jack down you should（）.
单项选择题 You are handling a mooring line and are instructed to Check the line.What should you do（）.