溶剂再生塔压力采用（）控制。
A、串级
B、单回路
C、分程
D、比值
参考答案：C
Home to ______ and gangsters, officials and laborers, refugees and artists, the city was, in its prime, a metropolis that exhibited all the hues of the human character.
A．magnates
B．magnets
C．machines
D．magnitudes
以和为原料合成乙胺丁醇
和
为原料合成乙胺丁醇