— ________ invention the wheel is! — I can’t agree more. It is an invention that changed the world.
—_____ you _____ your homework yet? —Yes, I _____ it ten minutes ago.
It’s necessary for you _____ exercise every day.
—Could you tell me _____? —Sorry, I don’t know.
The Greens _____ China for seven years.
— Thank you very much for the present you sent to me. — __________.