--Is it OK if I sit on this chair?--Sorry. .
The store sells sweaters _____ a very good price. We can buy one ______ 40 yuan.
—Is that your father? —No. It’s my uncle, my mother’s _____.
—Does Bob have vegetables for dinner? —______. But his sister has some carrots.
—Excuse ______. Is this ______ book?—Yes, thanks.
—Is that ______ volleyball?—Yes. Bill likes playing ______ volleyball. ______ volleyball is his.