—What does the sign over there read?―“No person ______ smoke or carry a lighted cigarette，cigar or pipe in this area．”

Your desk is covered with too many unnecessary things, including used papers and books. You’d better ________ some of them. 

The United States _______one of the lowest smoking rates －25.5 percent of the population.

I have to choose another way back home, because the road to my community _______ at the moment.

Look ! The building which _________now will be used as a library.