He __________ when I go to see him.
—Look! The man at the gate _______be our headmaster. He is always standing there every morning.—No, it_______ be him. He is holding a meeting in the office now.
—Your watch looks so nice. It must be expensive.—No. I ____ 20 yuan on it.
—How long have you________?—Since two years ago.
—Do you know whose car is it?—It belongs to_____. It isn’t ______.
The Chinese mainland has become the world's second______ market for iPhone.