51.   Some vehicles operate on a single fuel, while bi-fuel vehicles can switch between gasoline and an alternative fuel like ethanol.

52.   Switching between different computer programs to write and edit on one and to do administrative tasks on the other becomes fun once control of the basic moves is achieved.

53.   Switching between the two games creates a ratchet-like effect.

54.   Switching between user accounts is extremely quick and easy in Windows XP.

55.   The ability to switch between first- and third-person perspective is cool, too.

56.   The big problem with on-line networks today, Alsop said, is that the user has to switch between the computer operating system and the network application software.

57.   The controls are well designed, requiring only a single lever-push to switch between recording and playback modes.

58.   The group switched between rap and dance pop, sticking to black pop references.

59.   The New York Jets keep switching between Glenn Foley and Vinny Testaverde, contingent upon whether Coach Bill Parcells can see his shadow.