精馏操作中,若F、xF、q、R在不为的条件下,将塔顶产品量D增加,其结果是()
A.xD下降,xW上升
B.xD下降,xW不变
C.xD下降,xW也下降
D.无法判断
参考答案:C
The people upstairs __________ when I __________ to sleep last night.[ ]
A. danced; was going
B. were dancing; got
C. had danced; went
D. are dancing; get
对于已经“混到”阴床中的阳离子树脂如何分离?