Is it a ruler?
Yes, it is.
Is it a chair?
No, it isn't.
Where are the students?
In the library.
What subject it is?
It's Maths.
What's this?
It's a pencil case?
Where are the students?
In the canteen.
What subject is this?
It's Arts and Crafts.
Is it a rubber?
No, it isn't.
Where is the PE class?
In the gym.
What's this?
It's a book.
What's this?
It's a pencil.