31.   Previous research had focused on regions much farther from the black holes.

32.   Previous research had reached conflicting conclusions.

33.   Previous research had shown that malfunction of these genes makes fruit flies lose their sense of where they are.

34.   Previous research had suggested that the problem might stem from an abnormality in brain function that could be detected in a laboratory.

35.   Previous research has shown a link between heavy pot smoking and low sperm counts.

36.   Previous research has shown that such a disruption can cause the heart to go into repetitive activity, or ventricular fibrillation, which can lead to heart attacks.

37.   Previous research has yielded conflicting findings about the effects of high blood pressure, which can cause minor or temporary strokes that some investigators thought could impair brain function.

38.   Previous research had suggested that the reason drugs could kill the parasite yet leave the host unaffected was because the drugs had a higher affinity for parasite DHFR.

39.   Previous research has shown that Ritalin can cause side effects.

40.   Previous research has shown that trees and other vegetation slow the movement of stormwater, lower the total runoff volume and reduce flooding.