answer: #Person2# calls World Airline to book a plane ticket to London and #Person1# helps #Person2# to book.
documents: #Person1#: Thank your for calling World Airline. What can I do for you?
  #Person2#: I need to book a plane ticket to London.
  #Person1#: Round-trip or one-way?
  #Person2#: One-way.
  #Person1#: What date would you like to fly?
  #Person2#: Saturday, July 25.
  #Person1#: How many people will be traveling?
  #Person2#: Just one adult.
  #Person1#: Which class?
  #Person2#: Economy, please. Economy class is the cheapest, right?
  #Person1#: Right. Ok, the fare is $ 700.