Now air in our town is ____ than it used to be. Something must be done to it.
Friendship is _________ wine. The longer we keep it, the tastier it will be.
Don’t bother your father. He’s got a lot _________ his mind.
The parents can _________ afford his extra education abroad, because one of them has been out of work.
Since the war _________ in Syria in 2011, there have been a great many refugees(难民) running to nearby European countries.
We Chinese are _________ to protect the fishermen to fish in the proper area.