The average temperature at 40,000 feet above sea level is -60 F.
56
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
Pumice is the only rock that floats on water.
14
One 75-watt bulb gives more light than three 25-watt bulbs.
57
A cesium atom in an atomic clock beats over nine billion times a second.
43
4.5 pounds of sunlight strike the Earth each day.
27
Nylon is made from coal and petroleum.
42