answer: #Person2# tells #Person1# how often the print heads of the new printer should be replaced.
documents: #Person1#: I've just got a new printer. How often do I need to replace the print heads?
  #Person2#: Well, under normal conditions each head lasts about 5 000 copies or so. It depends on the user, but about once a month is average.
  #Person1#: So if I don't print out very much, it could last a lot longer?
  #Person2#: That's right. It could last six months or more. This model's designed for heavy use. Don't worry - you'll get an error message telling you when to change the head.