单项选择题
What is required to launch a boat stowed in a crescent davit?（）
A.Hoist the boat clear of the cradle B.Release the outboard part of the cradle C.Rig the tricing lines D.Crank the crescent out
单项选择题 What is normally used to pass a mooring line to a dock?（）
单项选择题 What happens to the efficiency of an anchor when it is moved from sand to mud?（）
单项选择题 What form of ice is of land origin?（）
