单项选择题
A.CO2 B.Methyl chloride C.R-22 D.Sulphur dioxide
Which of the following terms is used to identify the pr...
单项选择题Which of the following terms is used to identify the pressure of the liquid entering a pump?（）
A.Suction head B.Pump head C.Discharge head D.Total head
Ammonia when used as a refrigerant is valuable because ...
单项选择题Ammonia when used as a refrigerant is valuable because of its high efficiency, it is however （）.
A.toxic B.flammable C.explosive D.all of the above
Which of the following is operated from the main engine...
单项选择题Which of the following is operated from the main engine room console on an automated vessel?（）
A.Fire pump and lube oil pump B.Lube oil pump and distilling plant C.Distilling plant and shaft alley door D.Shaft alley door and fixed CO2 release
