There are _____ birds in the forest. A. millions of B. two millions of C. two millions
Xi’an is a city with many places of interest and ____ tourists come here every year.
—_____ 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.