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The word drug comes from the Dutch word droog (meaning "dry"). For centuries, most drugs came from dried plants, hence the name.
Cyanide works by making the human body unable to use oxygen.
Vaccines prevent between 2.5 and 4 million deaths every year.
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.
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