ASP驱是同时向地层中注入碱、表面活性剂和聚合物三种化学剂，提高采收率的机理是（）效应的综合结果。

A.多种

B.一种

C.三种

D.二种

Jim was a stout old gentleman, with a weather-beaten countenance .

A．body

B．skin

C．shoulder

D．passionate interest