补全对话。
A: Hello, Betty. ?
B: Hello, Tony. Our classroom is really big. There are 46 students in my class. ?
A: There are 45 students in my class.
B: ?
A: Yes, there are two maps on the wall, a map of the world and a map of China.
B: ?
A: No, there isn't a TV in our classroom. But there is a computer.
B: ?
A: It's on the teacher's desk. Oh, it's time for class(该上课了). Let's go. Bye.
B: Bye.
