2) Is our room big?
Yes, it is. It is big.
3) Is their dog black and white?
No, it isn't. It isn,t black and white.
4) Is her dress new?
Yes, it is. It is new.
5) Are his books good?
No, it isn't. It isn't good.
6) Are your children at home?
No, they aren't. They aren't at home.