单项选择题
What is the（）of the turning circle in mavoeuvring?
A.distance B.largeness C.diameter D.measurerment
单项选择题 What is required to launch a boat stowed in a crescent davit?（）
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?（）
