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Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Thyroid conditions may make getting pregnant impossible.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
Colchicine is a highly poisonous alkaloid originally extracted from a type of saffron plant that is used mainly to treat gout.
There are 20 feet of blood vessels in each square inch of human skin.
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