The service economy doesn't suggest that we convert our factories into laundries to survive.

A．imply

B．persuade

C．hurl

D．transform

按修筑位置不同将堤防分为江堤、（）、湖堤、库区围堤、蓄滞洪区围堤等。

A.土堤

B.石堤

C.土石混合堤

D.河堤