Try to spend as much time as possible            , please. [ ]

A．on having a rest

B．to take exercises

C．in your homework

D．relaxing yourself

根据排污和压井过程的差异，正循环压井法又演变为（）压井方法。

A.平衡点法

B.体积法

C.司钻法

D.工程师法

E.反循环压井法