Mrs White, why are you standing here?—I’m waiting for my son. He ___________ back from school.

Where is Mr. Green now ? I haven’t seen him for a few days .—He _____ to Hong Kong .

My father has decided to ________ smoking.—That’s good news for us.

Look at the boy running on the ground. Is it Davis?—It ______ be him. I saw him go to the teacher’s office just now.

Lin Hai and Dave __ his good friends.