采用色谱方法分离香豆素混合物，常选用的吸附剂有
A．硅胶
B．酸性氧化铝
C．碱性氧化铝
D．活性炭
E．中性氧化铝
参考答案：A,B,D
As far as I know, shopping online has many advantages, _____ the most important one is convenience.[ ]
A. during which
B. of them
C. of which
D. of whom
粉防己碱抗炎作用机制是（）
A．直接增强肾上腺皮质功能
B．稳定细胞膜减少致炎物质的释放
C．本身具有AcTH样作用
D．增强中性白细胞游走
E．以上均非
