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There are 20 feet of blood vessels in each square inch of human skin.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
It is difficult to obtain enough calcium without consuming milk or other dairy foods.
More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
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