Is it sailing?
Yes, it is.
Are they doing judo?
No, they aren't.
What is she doing?
She is skateboarding.
Is he surfing?
Yes, he is.
Are they playing table tennis?
No, they aren't.
What is she doing?
She is cycling.
What are they doing?
They are playing basketball.
What are they doing?
They are ice skating.
What is he doing?
He is skipping.