The cleaners must prevent the street ______.
—_______do you go skating ?—Twice a week.
Kate spends an hour ______ swimming every week.
—What are you going to be when you _______?—I want to be a teacher.
—Sorry , I’m busy. I can’t go fishing with you.—_______. I can ask Lily to go with me.
There are ______ students in this school.