What are they doing?
They are playing tennis
Are they doing judo?
They aren't doing judo. They are playing ping pong.
Are they doing gymnastics?
They aren't doing gymnastics. They are playing basketball
What are they doing?
They are doing judo
Are they playing basketball?
They aren't playing basketball. They are doing gymnastics
What are they doing?
They are playing soccer
What are they doing?
They are playing volleyball