answer: #Person2# helps #Person1# change 500 dollars into 3220 yuan and asks #Person1# to keep the exchange memo.
documents: #Person1#: Excuse me, will you change me some money, please?
  #Person2#: Of course.
  #Person1#: I'd like to change these dollars into RIB. Would you please tell me the exchange rate between American dollar and RIB?
  #Person2#: Sure. At present one dollar is equal to 6. 4392 yuan. How many dollars would you like to change?
  #Person1#: 500 dollars, please.
  #Person2#: Please wait for a moment. . . Now here is your Chinese currency. See if it's right. It's 3, 220 yuan. Please keep this exchange memo. You may need it for converting when you leave China.
  #Person1#: OK. Thank you for your help. That's very nice of you.
  #Person2#: It's my pleasure.