answer: #Person2# is sorry for taking #Person1#'s place.
documents: #Person1#: Excuse me. I'm afraid you're in my seat. You've moved my books.
  #Person2#: Oh, dear.
  #Person1#: You must have realized somebody was here.
  #Person2#: Oh, well, I looked around. There wasn't any other space. I waited a while and nobody came. I'm sorry if I've taken your place.