31.   The age is then confirmed by measuring levels of strontium, which slowly accumulates from the decay of heavier elements.

32.   The atmospheric observatory aboard the shuttle Atlantis has measured the level of ultraviolet radiation streaming to Earth from the sun with unprecedented accuracy, NASA researchers said Wednesday.

33.   The blood test measures levels of a protein called prostate-specific antigen, or PSA, which often rise when prostate cancer strikes.

34.   The company is conducting further studies to evaluate how measuring virus levels can help determine changes in therapy.

35.   The commission plans to measure arsenic levels in playgrounds later this year.

36.   The device will measure voltage levels outside the station and the potential for a dangerous electrical discharge as a result of addition of the powerful solar wing.

37.   The explosion was monitored mainly by measuring levels of chlorophyll, the green pigment of plants involved in the process of photosynthesis.

38.   The investigators measured carbon monoxide levels several ways.

39.   The level is measured using a complicated yardstick.

40.   The monitor will feature a wearable sensor patch and a wrist watch-type monitor that continuously measures glucose levels.