---What’s this? ---________.
—Where is Jack? —I noticed that he ________the teacher’s office just now.
—Don’t worry. Your uncle is coming to help you. —________he doesn’t come?
My friend’s flight had taken off _________ I got to the airport to see him off.
The monkey was seen _________off the tall tree.
—What do you think about the idea?—I am really against _________ a running race in the street.