If we______more attention to the signboards, we______our way.
A．had paid, would have lost
B．paid, would not lose
C．paid, would lose
D．had paid, would not have lost

有相对挥发度为2的理想溶液，用板式精馏塔分离。溜出液流量为100mol／h，回流比R=2，测得进入第n板的气液相组成分别为yn+1=0．8、xn-1=0．82，若塔板以气相组成表示的单板效率Emv=0．5，试计算离开第n板的气液两相组成。 点击查看答案

If Helen______the doctor's advice, she would not be sick now.A．should followB．had followedC．has followedD．follows

A.
A．should
B.had
C.has
D.follows

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