Test Drive | Page 59

Chapter
 2:
 Concept
 note

functions
  often
  change
  in
  time,
  as
  we
  see
  with
  the
  quat
  production
  in
  Yemen
  leading
  to
  changes
  in
  the

requirements
 of
 the
 water
 system.
 Authors
 refer
 to
 the
 importance
 to
 have
 adequate
 knowledge
 of
 the
 impact

of
  these
  ch