answer: #Person2# decides to send a box of books to Taiwan by airmail because #Person1# tells her although airmail is expensive, it's quicker and safer than by sea.
documents: #Person1#: Hi, good morning, Miss? what can I help you with?
  #Person2#: Good morning I'd like to mail this box of books to Taiwan.
  #Person1#: OK, please put it on this scale.Airmail or by sea?
  #Person2#: How long does it take to reach Taiwan by sea?
  #Person1#: Usually about two month.
  #Person2#: That's too long.How long does it take to reach Taiwan by airmail?
  #Person1#: About ten days.
  #Person2#: Then how much is that by airmail?
  #Person1#: Let me see.It ' s 57 dollars, 20 cents, including tax.
  #Person2#: That's a little bit expensive.
  #Person1#: Although it's expensive to send it by airmail, it's quicker and safer than by sea.
  #Person2#: I guess I have to send it by airmail.
  #Person1#: Do you want to ensure the contents, Miss?
  #Person2#: Yes, please.
  #Person1#: Please fill out this form, also please write the value of the items in this space.
  #Person2#: OK.