21.   Over all, a University of California at San Diego study of eight national parks in the state found that the greatest source of danger is not nature.

22.   Steve Brobeck, Consumer Federation president, said the study proved that by far the greatest source of wealth for even modest households is the value of their home.

23.   That, Olson said, is his greatest source of pride.

24.   The chief source of benzene was cigarette smoke, the single greatest source of indoor pollutants.

25.   The former buildings societies rely on savings and mortgages as their greatest source of profit, although they are trying to diversify into other products.

26.   The greatest source of annoyance is the level of customer support or, as many companies now label it, customer care.

27.   The greatest source of apprehension here, outside the phantom possibility of a terrorist attack, is the very real chance of a transportation breakdown.

28.   The greatest source of concern about his record centers on affirmative action.

29.   The greatest source of anxiety, naturally, is the protection of nuclear materials and radiation safety.

30.   The greatest source of insecurity for Bills fans involves the future of the Bills in Buffalo.