精馏塔压力降低会使系统内（）。
A.釜液中重组分浓度减少
B.塔顶重组分浓度降低
C.釜液量相对增加
D.塔顶气量相对增加
参考答案：D
The young pianist is very excited because the concert given by him has never been ________.[ ]
A. successful
B. more successful
C. most successful
D. the most successful
在Word 2003中，能实现取整的函数是ABS()。
