单项选择题
On a ship，watertight doors should be operated（）.
A.during abandon drill B.during fire drill C.weekly D.when the rig is being moved
单项选择题 On a ship，a fire drill shall be conducted once every（）.
单项选择题 Lifesaving regulations require that a fire drill include（）.
单项选择题 How long must the records of tests and inspections of fire fighting equipment on board a ship be retained on board?（）
