西晋灭亡后，曾统一黄河流域的是[ ]

A．刘裕

B．苻坚

C．王猛

D．司马炎

--- Do you really mean to prepare our lecture two months in advance?

--- Sure. Anyway,  ___________

A．a good beginning is half done.

B．a bird in the hand is worth two in the bush.

C．a fall into a pit, a gain in your wit.

D．the early bird catches the worm.