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Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
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.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
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