answer: #Person2# imagines the greatest change in the future will be the difference between humans and machines. #Person1# thinks #Person2#'s ideas are ridiculous.
documents: #Person1#: What changes do you think will take place in the next 50 years?
  #Person2#: I imagine that the greatest change will be the difference between humans and machines.
  #Person1#: What do you mean?
  #Person2#: I mean it will be harder to tell the difference between the human and the machine.
  #Person1#: Can you describe it more clearly?
  #Person2#: As science develops, it will be possible for all parts of one's body to be replaced. A computer will work like the human brain. The computer can recognize one's feelings, and act in a feeling way.
  #Person1#: You mean man-made human beings will be produced? Come on! That's out of the question!
  #Person2#: Don't get excited, please. That's only my personal imagination!
  #Person1#: Go on, please. I won't take it seriously.
  #Person2#: We will then be able to create a machine that is a copy of ourselves. We'll appear to be alive long after we are dead.
  #Person1#: What a ridiculous idea!
  #Person2#: It's possible that a way will be found to put our spirit into a new body. Then, we can choose to live as long as we want.
  #Person1#: In that case, the world would be a hopeless mess!