31.   These calcified shells contain varying traces of oxygen isotopes that indirectly tell scientists how much water was locked up as ice at any given time.

32.   Warm and talkative, Alvarez has a voice that barely contains traces of her Dominican roots.

33.   Within seconds, the instrument can tell whether that vapor contains any traces of a dangerous substance.

34.   Parts of population contain traces of original Indian peoples, but indigenous cultures died out long ago.

35.   A spokesman for the environment department, Irma Paulme, said mine waste water normally contains traces of copper, zinc, cadmium, lead and molybdenum.

36.   A two-ton block of metal originally said to be pure platinum may only contain traces of the precious metal, experts said Thursday.

37.   After testing six samples in all, they finally found two fields that did not contain traces of modification.

38.   Al-Khalidi was stripped of the medals after a urine sample was found to contain traces of the stimulant ephedrine.

39.   Analysis by a Hong Kong laboratory has shown the waste contains traces of mercury, a poisonous metal.

40.   Army scientists and the FBI said Friday that the substance was talc and contained no trace of the deadly bacteria.