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In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
The horizontal fraction bar was introduced by the Arabs.
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