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There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
According to the FDA, adverse drug events harmed or killed approximately 1,200,000 people in the United States in the year 2015.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Thyroid conditions cause a higher risk of fibromyalgia and chronic fatigue syndrome.
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