单项选择题
A.few
B.little
C.a little
D.less
单项选择题 Because of the reduced （）in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.
单项选择题 Because of the reduced （） in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.
单项选择题 In a vacuum distillation system, the case is the higher the pressure, （）.