单项选择题
A.vacuum drag from the auxiliary condensate system
B.individual vacuum pumps
C.a single non-condensing air ejector
D.a two stage air ejector
单项选择题 The heated feed-water entering any flash chamber of a flash-type evaporator will（）
单项选择题 On a multistage flash-type evaporator, the flash chamber is （）
单项选择题 Early models of the flash-type evaporators used a separate shell-and-tube heat exchanger as the air ejector condenser.More recent models use a combined air ejector condenser with the（）