What's this?
It's luggage.
Who's he?
He's the security guard.
What's he doing?
He's getting his boarding card.
What's he doing?
He's going to his/the gate.
What are they doing?
They're boarding the plane.
Who's he?
He's a pilot.
Who's she?
She's a flight attendant.
What's he doing?
He's checking in his luggage.
What's she doing?
She's showing her passport-
Who's he?
He's a passenger.
What's he doing?
He's going through security.