—What does the sign over there read?—No person ________smoke or carry a lighted cigarette ,cigar or pipe in this area. 

—Can you sing or dance?     —_____.

---Look at the boy running on the playground. Is it David? ---It ______ be him. I saw him go to the teachers’ office just now.

A giant of a man was standing in the doorway. His face was almost completely hidden by a long and untidy hair and a wild beard, but you ______ make out his eyes, shining like black beetles under all the hair.

—What do you think of John?—He’s a good boy, but he ______ be really stubborn at times.