单项选择题
A.to cut down the amount of cooling water needed
B.to prevent an excess amount of cooling water from being discharged to the bilges
C.to supply hot water to the evaporator for more economical operation
D.None of the above is tree
单项选择题 When distilling sea water the cooling water discharging from the distiller is fed back to evaporator as feed water （）.
单项选择题 In a vacuum boiling evaporator, the fresh water generated is pumped out by （）.
单项选择题 With a vacuum boiling evaporator, the remainder of sea water fed to the evaporator is pumped out by （）.