单项选择题
Each open lifeboat carried on a vessel on an international voyage must have（）.
A.hand-propelling gear B.a davit span with at least 2 lifelines C.a mast and a sail D.a motor
单项选择题 Each lifeboat must be lowered and maneuvered in the water at least once every（）.
单项选择题 During the required periodic abandon ship drill aboard a ship，each person not assigned duties in the muster list is（）.
单项选择题 During a fire drill on a ship，what action is required?（）
