answer: #Person1# recognizes Lucy for Lily by mistake because they are twins. #Person1# and Lily are in the same class.
documents: #Person1#: Hi, Lily, what a surprise to see you here! Aren't you on a holiday with Mike in Paris now?
  #Person2#: Sorry, I'm not Lily. I'm her sister Lucy.
  #Person1#: Gosh, you two really look like each other. Are you twins?
  #Person2#: Yes. She is 20 minutes older than me.
  #Person1#: It must be interesting to have a twin sister.
  #Person2#: Well, not so interesting. We have to share almost everything. So are you a friend of Lily's?
  #Person1#: We're just in the same class. Are you seeing anyone off here?
  #Person2#: In fact, I'm taking a flight to Beijing. I like traveling. What about you?
  #Person1#: I came with a friend. She's going to New Zealand for her summer holiday.