单项选择题
A foam-type portable fire extinguisher is most useful in fighting a fire in（）.
A.generators B.oil drums C.the bridge controls D.combustible metals
单项选择题 A fixed CO2 system on a ship with a capacity of over 300 lbs (136 kilograms) CO2 which protects spaces other than tanks must have（）.
单项选择题 A fire starts on your vessel while refueling. You should FIRST（）.
单项选择题 A combination or all-purpose nozzle produces（）.
