属于生物碱的是（）。
A.A
B.B
C.C
D.D
E.E
参考答案：E
解析：
A为苯丙酸类，B为萘醌类，C为单萜类，D为香豆素类，E为生物碱类。
——Did you see Lucy last night ?She must have left home as she was wondering round the town at midnight .
——The fact that she was wondering round the town at midnight
she had left home for good .
A．was not meaning
B．does not mean
C．was not mean
D．would not mean
什么是等速过滤和变速过滤？两者分别在什么情况下形成？属于等速过滤和变速过滤的滤池分别有哪几种？
