answer: #Person2# measures #Person1#'s waist and assists #Person1# in trying on trousers. #Person1# finally finds a perfectly-fit one and he will buy it.
documents: #Person1#: Show me a smaller pair of trousers, sir. I am not that fat, you see.
  #Person2#: You've come to the right place. We've got various styles and sizes recently. How much do you measure around your waist?
  #Person1#: I have no idea. Measure me, please.
  #Person2#: OK! 2 Chi round. Try this one. Maybe it's of your size.
  #Person1#: ( After trying ) I'm afraid it's still too fight around the stomach.
  #Person2#: Let me check the stock. How about this one?
  #Person1#: ( After trying ) Mm, a perfect fit. How much?
  #Person2#: 150 Yuan.
  #Person1#: A little expensive. But I'll buy it anyway. It's hard for me to get a perfect one. Here is 200 Yuan.
  #Person2#: Here's your change, 50 Yuan. Welcome back again.