2) Is Mary watching TV at the moment?

No, she isn't. She is having shower right now.

3) Does this box weigh more than ten kilos?

Yes, it does. It weighs twelve kilos.

4) Do these trousers cost 80 pounds?

Yes, they do.

5) Are Kim and Tina learning German at school this year?

No, they aren't. They are learning French.

6) Is Keith studying for exams this month?

Yes, she is.