HPLC外标法测定氨苄西林含量的计算式（）
A.
B.
C.
D.
E.总青霉素含量%-降解产物含量%
参考答案：B
The following day she didn't go to the club._____, she took a short walk in the park nearby. [ ]
A. Therefore
B. However
C. Instead
D. Besides
现代政党诞生的前提条件是( )
A．民主制度的确立B．资产阶级的发展C．封建制度的腐败D．科学技术的发展
