Who is he?
He is the security guard.
Who are they?
They are the passengers.
What is the passenger doing?
She is going through security.
What are the passengers doing?
They are showing their passports.
What is it?
It's a boarding pass/ a boarding ticket / a flight ticket.
What are the passengers doing?
They are checking in their luggage.
What are the passengers doing?
They are boarding the plane.
Who is she?
She's the pilot.
Who is she?
She's a flight attendant.
