What were they doing?
They were singing.
What was the mouse doing?
The mouse was cooking.
What was Lisa doing?
She was dancing.
What was he doing?
He was eating.
What was he doing?
He was surfing.
What was she doing?
She was taking photos/pictures.
What was he doing?
Hewas running.
What was she doing?
She was playing the guitar.
What were they doing?
They were skating / roller skating / rollerblading