单项选择题
On a ship，how many ring buoys are required to have a buoyant line attached?（）
A.One ring life buoy B.One ring life buoy on each side of the ship C.Three ring life buoys D.Two ring life buoys on each side of the ship
单项选择题 On a ship，firefighting equipment must be inspected once every（）.
单项选择题 On a ship，a fixed carbon dioxide or other approved system must be installed（）.
单项选择题 On a ship，a fire drill shall be conducted once every（）.
