单项选择题
On a small boat，which knot is best suited for attaching a line to the ring of an anchor?（）
A.Clove hitch B.Figure-eight knot C.Fisherman's bend D.Overhand knot
单项选择题 On a ship，when may a work vest be substituted for a required life preserver?（）
单项选择题 On a ship，watertight doors should be operated（）.
单项选择题 On a ship，how many ring buoys are required to have a buoyant line attached?（）
