21.   But they also are mind-boggling, since their interpretation requires use of a sextant, calculator and a doctorate in astronomy.

22.   Critics of the law said it has spawned a host of lawsuits from convicts who claim that their religion requires the use of marijuana and other banned activities.

23.   Disposal of hazardous materials is much more rigorous and requires the use of special landfills.

24.   Each challenge requires the use of a team timeout.

25.   During that period, the urgent demands of the war on terrorism may require the use of U.S. forces elsewhere.

26.   European sailors led the charge against the state law that requires the use of U.S. Coast Guard-approved life jackets.

27.   For their part, state Medicaid officials want to be able to require the use of HMOs without getting permission from the federal government.

28.   For years, the only option was to have the lens surgically removed, which left a focusing problem that required the use of glasses with unusually thick lenses.

29.   He has dodged questions about whether he would veto spending bills that required use of the Social Security money.

30.   He said that the American goal was a peaceful and united Europe, but that achieving that end now requires the use of force.