甾体激素类药物均具有的基本结构为（）
A.环戊烷并多氢菲母核
B.丙二酰脲母核
C.β-内酰胺环
D.对氨基苯磺酰胺母核
E.氨基嘧啶环
参考答案：A
－Happy New Year to you!
－_______. [ ]
A. You're welcome
B. The same to you
C. Congratulations
–We need a person badly to be in charge of this design.
--_________ the new comer have a try?
A．May
B．Shall
C．Will
D．Need
