单项选择题
A.canister-type gas mask
B.fresh-air breathing apparatus
C.self-contained breathing apparatus
D.combustible gas indicator
单项选择题 Which of the following statements represents the correct action to take when three crew members discover a fire?（）
单项选择题 A new ocean going ship of 2000 gross tons having an inoperative oily water separator may dispose of its bilge slops by （）.
单项选择题 At the earliest indication of fire aboard your vessel, you must FIRST（）.