具有极性吸附作用的是（）
A．活性炭
B．硅胶（含水量低于10%）
C．纸色谱
D．阳离子交换树脂
E．聚酰胺
参考答案：B
I used to _________. But now I get used to _________doing everything. I’m successful at last.
A. give up; keeping B. giving up; keeping C. giving up; keep
