单项选择题
An inflatable liferaft should be lifted back aboard the ship by using（）.
A.the single hook at the top of the raft B.two lines passed under the raft C.the towing bridle D.All of the above
单项选择题 After using a CO2 extinguisher on a ship，it should be（）.
单项选择题 After each reading of an oxygen indicator，the instrument should be purged with（）.
单项选择题 Actuating the CO2 fixed system causes the shutdown of the（）.
