Listen! There is a knock on the door．Who _____ it be?—It must be Jack．Just now I sent for him．

There are about _______ students in their school now..

Do you know who took the students to the old people’s home, Tony?—Well, Mr. Smith _______.

In the past ten years, our hometown named Yandu（盐都） _____a lot.

Mr. Green, a famous writer, ____________ our school next week.