What is she doing?
She is playing basketball.
What is she doing?
She is swimming.
What is he doing?
He is playing football.
What is he doing?
He is riding a bike.
This is...
sport (sports)
What is she doing?
She is playing the piano.
What are they doing?
They are watching television.
What is she doing?
She is playing tennis.
What is he doing?
He is playing the guitar.