药物与含量测定:硫酸庆大霉素().
A.汞量法
B.硫酸汞盐法
C.高效液相色谱法
D.气相色谱法
E.抗生素微生物检定法
参考答案:E
— It is Sunday today, isn't it?
— Yes. We _____ to school today.[ ]
A. don't need go
B. need to not go
C. needn't to go
D. don't need to go
已知蒸发1mol Br2(l)需要吸收的能量为30kJ,其它相关数据如下表
则表中a为 [ ]