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Blood is approximately twice as thick as water because of the cells and other components found in it.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
The word drug comes from the Dutch word droog (meaning "dry"). For centuries, most drugs came from dried plants, hence the name.
The horizontal fraction bar was introduced by the Arabs.
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