—What do you need to say?—No person         smoke or carry a lighted cigarette in this special room.

–Whose volleyball is this?–It _______ belong to Carol. She loves volleyball.

The police still haven’t found the lost child, but they’re doing all they             .

A hard-working man _____ become a great scientist, but a great scientist _____ be a hard-working man.

—May I smoke here?    —If you _____, choose a seat in the smoking section.