21.   And it took as little as one-third the blood levels of the drug typically associated with street use to produce the effect.

22.   And many herbs have several active ingredients that work together to produce an effect that could not be realized with a single synthetic drug.

23.   But it produced no effect.

24.   But that did not work because the fields were simply too weak to produce an effect.

25.   But some experts say there is reason to believe that other cancer screening tests produce similar effects, but perhaps not as pronounced.

26.   Coach Vince Tobin said the Dallas win could produce similar effects.

27.   Ecstasy produces its effects for four to six hours, he said, yet no one knows how the drug works.

28.   Draining the swamps has made parts of them useable for human purposes, but the drained water has produced negative effects downstream.

29.   Even a small difference in the activity of a high-level regulatory gene could produce significant effects in the developing animal.

30.   Games, he argued, produce entrainment effects as well.