answer: #Person2# tells #Person1# how to travel by air.
documents: #Person1#: How can I travel by air?
  #Person2#: Have you traveled by air before?
  #Person1#: No, this is the first time.
  #Person2#: Let me tell you. First you must buy a ticket.
  #Person1#: Yes, I know.
  #Person2#: Then you must go to the airport.
  #Person1#: Is that all?
  #Person2#: Not Yet. Listen to me. Don't forget to take your ID card with you.
  #Person1#: What's an ID card?
  #Person2#: Something like a passport.
  #Person1#: Can I board the plane now?
  #Person2#: No, you also need a boarding pass.
  #Person1#: Thank you. Now I know how to travel by air.