----Must I finish the jod at seven o’clock?----No, you___________

_Could I go to the movie this Sunday, Dad?Yes, you_____. But you ______ come back before nine.

--______ we clean the classroom at once? --No, you _____. You____ clean it after school.

—People find it hard to get across the river．—I think at least two bridges         over it．

— I heard they went skiing in the mountains last winter. — It ________ true because there was little snow there.