One of the principal dangers inherent in liquefied petroleum gas is（）.

单项选择题Inerting means（）.

A.the introduction of inert gas into a tank with the object of reducing the oxygen content to below 8% by volume
B.the introduction of inert gas into a gas free tank for the purpose of reducing the oxygen content to below 8% by volume
C.the introduction of inert gas into a cargo tank during cargo discharge to replace the volume of discharged cargo
D.All of the above

单项选择题In setting the valves on a steam-smothering system on a tank vessel，the master control valve to cargo tanks should be（）.

A.open and individual tank valves open
B.open and the individual tank valves closed
C.closed and the individual tank valves closed
D.closed and the individual tank valves open

单项选择题If you are fighting a fire below the main deck of your vessel，which action is most importantconcerning the stability of the vessel? （）

A.Shutting off electricity to damaged cables
B.Pumping fire-fighting water overboard
C.Maneuvering the vessel so the fire is on the lee side
D.Removing burned debris from the cargo hold

单项选择题If a leak occurred while loading diethylenetriamine，the chemical data guide indicates you would smell an odor similar to（）.

A.ammonia
B.rotten eggs
C.gasoline
D.None of the above

单项选择题Hoses used for cargo transfer operations must be tested and inspected at specified intervals by（）.

A.a representative of the Captain of the Port
B.the operator of the vessel or facility
C.a representative of the National Cargo Bureau
D.low inert gas temperature