Is this your wallet?
Yes, it is.
Who's that?
It's my teacher.
Are these your sunglasses?
Yes, they are.
Who are these girls?
They're (they are) my sisters.
Is that your mom?
Yes, it is! She's busy making dinner.
Are _____ your parents?
those. (Yes, they are)
Are those your books?
Yes, they are.
What is this?
This is a notebook.
What things do you have in your school bag?
I have a cell phone, wallet, keys, a pair of reading glasses, and an MP3 player!
Are these your keys?
Yes, they are.