When a tank is to be gas freed after washing，the concentration of hydrocarbon vapour should be reduced by purging the inerted cargo tank with ______．
A.the oxygen
B.the gas
C.the inert gas
D.the hydrocarbon vapour
第1题：
A cargo tank that is initially gas freed，can be inerted by introducing inert gas by a process known as ______.
A.dilution
B.displacement
C.precipitation
D.Either A or B
第2题：
Which step is NOT generally taken when gas-freeing a tank? ______.
A.Washing the tank interior with sea water
B.Application of degreasing solvents
C.Removal of corrosion products and sludge
D.Fresh air ventilation
第3题：
A.Global buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freed
B.Thread buffers are allocated when a client connects, and are freed when the client disconnects
C.Buffers that are needed for certain operation are allocated when the operation starts, and freed when it ends
D.User buffers are allocated at server startup and freed when the user is dropped
E.All dynamic buffers that are set with a SET GLOBAL statement immediately get allocated globally, and are never freed
第4题：
What is NOT a requirement for the safe and effective use of a crude oil washing system ________．
A.Strip all tanks and remove the bottom residue
B.Use an inert gas system while washing tanks
C.Use portable washing machines to reach areas obscured by structural members in the tanks
D.Debottom the tank used as the source for the tank cleaning machines
第5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
第6题：
You are cleaning the tanks after carrying a cargo of crude oil. Which statement is TRUE?
A.Washing water should be recirculated if possible because it has the same electric potential as the cargo tank being cleaned
B.The hoses to portable cleaning machines should be disconnected before the machines are removed from the tank
C.The principal hazard with steaming cargo tanks is raising the ambient temperature above the flame point of the cargo residue
D.Steam cleaning and water washing are both capable of generating electrostatic charges within a tank
第7题：
You are testing a tank that contained gasoline by using a combustible gas indicator．Under testing，the tank sample caused the needle to move rapidly to 100 on the dial then fall to zero．What is the concentration of flammable gas ________．
A.Less than the flammable range
B.Within the flammable range
C.Over the flammable range
D.The explosimeter is defective and giving a false reading
第8题：
How should cargo tank hatches be protected when the ullage opening is open and the tank NOT gas free?
A.With gooseneck vents
B.With warning signs
C.With flame screens
D.With pressure-vacuum relief valves
第9题：
The deck water seal of the inert gas system ______．
A.Cools the inert gas and prevents soot from entering the cargo tanks
B.Acts as an emergency shutdown when inlet pressures exceed the safe working pressure
C.Prevents the backflow of hydrocarbon gasses into nonhazardous areas
D.Relieves sudden large overpressures in the system
第10题：
When a non-volatile cargo is carried in a tank that has not been previously gas freed，then that tank shall ______．
A.be purged with hydrocarbon gas prior to loading
B.be gas-freed after loading operations
C.not be maintained in an inert condition
D.be maintained in an inert condition