单项选择题
A.Diffusers B.Compressors C.Steam boilers D.Soot blowers
（） provide the water to the pistons.A.Pneumatic pipesB....
单项选择题（） provide the water to the pistons.
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
