(serve) __ the people well is our duty.
The president is elected directly by the people by a______.
forced to introduce still further innovations for the reasons given above.
Shefeltinsulted,andobviously________(任何劝他留下来的企图都是徒劳无用的).
He was a very serious and gifted individual, and __ (他不允许任何事情干扰他的研究), not even under the most extreme circumstances.
We tend to realize the value of __ (我们所拥有的东西) until there is no more of it in our life.