answer: #Person2# recommends a phone card for #Person1#'s daughter. #Person1# wants a prepaid one and #Person2# tells her there is a sales promotion. #Person2# decides to get three phone cards.
documents: #Person1#: Can I help you, Ma'am?
  #Person2#: I need a phone card for this new cell phone.
  #Person1#: Cool phone. What kind of phone card do you want?
  #Person2#: It's for my daughter who is still a senior high school student.
  #Person1#: Then the M-Zone will be suitable.
  #Person2#: What's special with the service?
  #Person1#: You know students use tested message service. And they provide favorable service for that.
  #Person2#: That's nice. And I need a pre-paid phone card.
  #Person1#: Oh, there is a sales promotion for it now.
  #Person2#: Oh, good. Then what is it?
  #Person1#: If you buy a pre-paid phone card worth 100 yuan today, you will get 50 yuan for free.
  #Person2#: May I have two of them?
  #Person1#: Sure. As many as you want.
  #Person2#: Okay, then a third one for my husband too.