31.   But when the problem persists for several nights or even weeks, insomnia can be more than simply aggravating and inconvenient.

32.   But, for now, the multiple pregnancy problem persists.

33.   But, he added, if problems persist into next week, passengers could face havoc finding alternative flights during the busy school vacation week.

34.   Counseling may be helpful if the problem persists.

35.   Despite the advantages that the Internet offers to the disabled, technological problems persist.

36.   Earlier today, a separate government report showed problems persisted in merchandise trade into the second quarter.

37.   Economists and OPEC watchers are split on whether the oil problem will persist.

38.   Easton Aluminum has since developed a clap system for American skaters, but equipment problems persist.

39.   Even now, many problems persist.