单项选择题
A.Pneumatic pipes B.Hydraulic pipes C.Telescopic pipes D.Operating gas pipes
（） is used for washing and drinking.A.The ballast syste...
单项选择题（） is used for washing and drinking.
A.The ballast system B.The salt water system C.The bilge system D.The domestic system
（） at the end of the distribution pipe ensures that ade...
单项选择题（） at the end of the distribution pipe ensures that adequate pressure is maintained by the pump.
A.A relief valve B.An alarm C.A pressure gauge D.A non-maim valve
（） allows for expansion and water make up in the water ...
单项选择题（） allows for expansion and water make up in the water cooling system.
A.A top tank B.A head tank C.A head valve D.A drain tank
