地下水按埋藏条件分为（）、（）和（）。
参考答案：上层滞水、潜水、承压水
平面内两点A、B关于______对称．
— ______________________
— This afternoon. [ ]
A. Where are you going?
B. What are you going to do?
C. When are you going?
D. What's your name?
