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（）.
A.continue ahead at slow speed B.continue ahead at half speed C.stop your engines D.back down on your engines
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（）.
单项选择题 Which will cause a wire rope to fail（）.
