31.   Earlier this year the FCC formally decided to tighten these rules.

32.   Eligibility rules could be tightened to eliminate mistakes.

33.   Environmentalists also warn that converting to diesels will limit opportunities to tighten pollution rules even further someday.

34.   Even when governments try to tighten the rules, people may find ingenious ways around them, if the incentive is great enough.

35.   For another, the patent office has tightened its rules in recent years and has declared that some kinds of DNA are not patentable.

36.   For example, both bills would tighten the rules that govern tax-free mergers and acquisitions, known as Morris Trust transactions.

37.   For one thing, Congress has tightened rules limiting lobbying by ex-senior government officials.

38.   Frelick said Europe and the United States, worried that millions of people would flee once-closed societies for refuge in their countries, have tightened their rules.

39.   He also seeks to close loopholes that allow program abusers to escape punishment and tighten rules governing the entry of doctors and other health providers into the programs.

40.   He also seeks to close loopholes that allow program abusers to escape punishment and to tighten rules governing the entry of doctors and other health providers into the programs.