单项选择题
Portable fire extinguishers must be provided for the cargo tank area of an unmanned tank barge（）.
A.only when fully loaded B.if one or more tanks are full C.when transferring cargo D.only when the barge is being towed
单项选择题 Portable CO2 fire extinguishers should NOT be used to inert a space containing flammable liquids due to the danger of（）.
单项选择题 Overhauling a fire in the living quarters on a vessel must include（）.
单项选择题 Operation of the valve control release on a fixed CO2 system must immediately（）.
