精馏过程中,气液相间的()差,是传质的推动力。
A、温度
B、密度
C、浓度
参考答案:C
Sometimes I can’t help wondering what’s the matter with Tom.I can’t stand it that he often_____ me and talks with the other students around him.
A.upsets
B.recognizes
C.concerns
D.Ignores
换热器为什么一般尽量采用逆流布置?