What is it?
It's the Moon.
What are they?
They are tourists.
What is it?
It's air.
What is it?
It's Earth.
What is his job?
He's an engineer.
What is it?
It's space.
What is his job?
He's a businessman.
What is it?
It's a rocket.
What is his/her job?
He/she is an astronaut.