在水泥混凝土中加入减水剂，可以______。

A．提高混凝土的强度

B．改善混凝土的和易性

C．缩短混凝土凝结时间

D．在强度维持不变的情况下，可节约水泥

E．提高混凝土的密实性

—Excuse me. Can you tell me _______?

—Sure. There's a good restaurant on Main Street. [ ]

A. where I can post letters

B. what movie I can see here

C. how I get to the bus station

D. if there's a good place to eat in