— I think Mr. Zhang may be in his office.— No, he _____ be there. I saw him ____ there just now.

---__________ I have a ticket , please?                                          ---Sorry,sir. All the tickets were sold out ten minutes ago.

 — What does the sign over there say? — No person _________ bring drinks into the student computer room. 

I _______ keep dogs for protection, but now I keep them as pets.

Sometimes the boy is a bad-tempered child, but he ____ be quite lovely when he wishes．