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The average adult has about 21 square feet of skin.
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
These illustrations show Ellen Craft, a slave with and without a disguise. She dressed “as a disting
Rank-order correlations show that differential consistency remains high from childhood through late ...



