---He hardly spent any time on his subjects, ________?---________, so he does badly in his lessons.
—_____ 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. — __________.