Betty: In our school, there are 20 students in a class. In my classroom, there's a blackboard and there are
         22 desks.
Daming: There are 46 students in my class. That's 24 boys and 22 girls. No, that's not right. There are 25
             boys and 21 girls. There are 48 desks.
Betty: Are there any computers on your desks? Is there a computer on Miss Li's desk?
Daming: No, there isn't. There isn't a computer on Miss Li's desk. And there aren't any computers on our
             desks. Are there any computers in your classroom?
Betty: No, there aren't.

1. In Betty's school, there're ___________ students in a class.
2. There's a ___________ in Betty's classroom.
3. In Darning's class, there're ___________ students.
4. ___________ has got 21 girl classmates.
5. Are there any computers in Betty's classroom? ___________.