What's she doing?
She is riding a bike.
What's he doing?
He is playing with a ball.
What's she doing?
She is jumping.
What's he doing?
He is playing with a boat.
What's she doing?
She is playing with a ball. / She is playing football.
What's he doing?
He is running.
What's she doing?
She is skipping.
What is she doing?
She is swimming.
What's he doing?
He is riding his scooter.
What's he doing?
He is riding his bike.