单项选择题
A.When attacking the fire directly
B.When using a steam smothering system
C.When using the fixed CO2 system
D.All of the above
单项选择题 When possible，what should be the FIRST step in combating a fire on deck resulting from a cargo overflow or a leaking cargo line?（）
单项选择题 When possible，what is the FIRST step in fighting an engine fuel-pump fire which results from a broken fuel line?（）
单项选择题 When must a dry chemical fire extinguisher be recharged?（）