--- Would you mind giving your advice on how to improve our efficiency?

--- If you make      most of forty-five minutes classes day after day, there will be       switch in grades.

A．/; /

B．the ; a

C．/; a

D．the; /

“三个代表”重要思想的实质和核心是（）。

A．始终保持中 * * 党的先进性

B．解决国内矛盾

C．解决国际争端

D．建设什么样的党，怎样建设党