31.   A second study provides encouraging news about the safety of a drug given to reduce the threat of heart attack in patients undergoing balloon angioplasty.

32.   A new study provides some relief, by suggesting that one dietary change may help protect against both diseases.

33.   A study released today provides substantial new evidence that air pollution from auto exhausts and smokestacks is killing people worldwide.

34.   But a new study may provide some clues on how to head off that progression.

35.   But a second study provided mixed results.

36.   But it is problematical whether the study will provide definitive answers, and especially whether it will provide a clear enough idea of what the pre-Columbian ecosystem was like.

37.   But its next such study will provide little comfort to ban-the-bomb activists.

38.   But the New Orleans study provides additional evidence to the contrary.

39.   But the study does provide a benchmark for future surveys.

40.   But the new study may provide some clues.