David and Jack are friends. They are Canadians, but they don't live in Canada. They live in China now. They are in No. 2 Middle School. They are in the library now. There are many books in the library. They borrow books from it. David borrows three books and Jack borrows two books. It's five in the afternoon. Jack closes the windows and David closes the door. "Thank you, David. Thank you, Jack." says the teacher. David and Jack say, “You are welcome.”