31. Because the light signals were tripped during his performance, Valiantine did not collect the award. 32. A light signal fades after 250 to 375 miles. 33. Another light signals if the user has unread e-mail. 34. Both signalboxes control a mix of semaphore and colour light signals with mechanically operated points. 35. This clock measures the time of day, primarily based on input from outside light signals . 36. But at journey's end, these light signals must be processed and converted to electronic signals. 37. At level crossings Athens Tram uses special light signals which are coordinated with road traffic lights. 38. Within Class Delta AGL low approach with " tailhook " extended and observe tower light signals . 39. Wang's experiment uses another property of light signals . 40. Today, only electrically operated light signals are used.
