answer: #Person1# doesn't know how to lose weight. #Person2# recommends dancing machines which people can move on them as if they are really dancing. #Person1# thinks it's interesting and would like to buy one.
documents: #Person1#: You see, I'm getting much fatter than before. I'm always worried I've no idea how to lose weight.
  #Person2#: You should do some exercise every day. That is the best way to keep you healthy and strong.
  #Person1#: You know, I don't want to move about at all.
  #Person2#: You'd better not watch too much TV. Recently, dancing machines have been popular in China. I suggest buying one.
  #Person1#: What is the dancing machine?
  #Person2#: Oh, you may see one in shopping centres. It's easy to learn how to use it. What you ought to do is to dance on such machines with loud disco music, stepping forward and backward, left and right according to the directions on TV, as if you are really dancing.
  #Person1#: That sounds interesting! But is it useful to help me keep fit?
  #Person2#: Sure. When you finish dancing, you'll be out of breath.
  #Person1#: Where can I find one?
  #Person2#: You may go to the Friendship Store.
  #Person1#: Is it expensive?
  #Person2#: I don't think so. It only costs 800 yuan.
  #Person1#: All right. I'd like to buy one.