A
B
C
D
实验
除去Cl2中含有的少量HCl
蒸干NH4Cl饱和溶液制备NH4Cl晶体
制取少量纯净的CO2气体
分离CCl4萃取碘水后已分层的有机层和水层
装置
A:A
B:B
C:C
D:D
抛物线y=﹣2x2的准线方程是( )
—Look! All students in the classroom are preparing for the coming exams_____.
—Yes, the exams are very important to them.