answer: #Person1# asks #Person2# how the trip was going. #Person2# compares Shanghai and London from different aspects.
documents: #Person1#: How's your trip going?
  #Person2#: Oh I'm enjoying myself but it's so hot here
  #Person1#: Isn't London hot in the summer?
  #Person2#: Well it can be but Shanghai is much warmer than London.
  #Person1#: I see. What about transport? How does Shanghai compare to London?
  #Person2#: Actually I think the buses and trains here are more modern.
  #Person1#: And what about the number of people on the streets?
  #Person2#: Oh, I think Shanghai is much more crowded than London.