21.  There are three primary ways in which computer users leave tracks in a computer systems.

22.  Trades have become the primary way of building championship teams.

23.  Today, mice are the primary way folks interact with their PCs, thanks to graphical interfaces and Web browsers.

24.  When all is said and done, though, car pools are the primary way students go home and get back.

25.  While CD-ROMs are now the primary way software is distributed, the Internet instead has become the primary way to deliver information that includes text, images and sound.

26.  Environmental groups insist that giving legal teeth to the treaty, including the possibility of sanctions, is the primary way to make sure countries abide by it.

27.  He assured me that NATO is going to be the primary way to keep the peace in Europe.

28.  There are two primary ways to call a special session, which would be necessary to pass legislation before the body convenes in March.

29.  There are two primary ways to call a special session.

30.  There are two primary ways to summon a special session.