answer: #Person2# buys a pen and a pencil with #Person1#'s assistance.
documents: #Person1#: Can I help you?
  #Person2#: How much is this pen?
  #Person1#: Ten Yuan.
  #Person2#: And how much is this pencil?
  #Person1#: One Yuan.
  #Person2#: Here's fifteen Yuan.
  #Person1#: And here's your change. Please check if it is correct.
  #Person2#: OK, that's right.
  #Person1#: Welcome to come again.
  #Person2#: OK.