21.   Still, computers have replaced the card catalogue, whose cards now serve as wallpaper.

22.   The explanation, of course, is that computers have replaced more traditional ways of doing things.

23.   The new computer replaces the troublesome Mir motion-control device that faltered three times in as many weeks prior to the launch of Atlantis last week.

24.   The new computer will also replace the aging host computer at the Boston Center, in Nashua, N.H., which has had numerous computer problems this year.

25.   The new computer will replace the aging host, or primary, computer used in the New York Center.

26.   When computers replaced typewriters, copy boys, and by then, copy girls, were no longer as vital to the operation as they had been.

27.   Years ago Fallows teased Barbara Wallraff, the resident grammarian at The Atlantic Monthly, asking her when a computer might replace her.

28.   A spare computer aboard Alpha replaced one of the backups, and its hard drive had been reformatted Monday.

29.   Hoffman insists computers will never replace old-fashioned flesh-and-bone actors and stunt workers.

30.   If necessary, computers may replace people.