—Where are your children?—I had no idea. But when I left home this morning, I saw them _______ a football in the yard.
He used to watch TV or ______ computer games at home on weekends.
—How do you study _________ a test? —I often study _______ a group.
This is ______ book. They like it very much.
______ his shoes under the bed?
There is a big supermarket near my house. It’s very easy _________ it.