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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.
The human body produces and destroys 15 million blood cells every second.
Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
Long-term mental and physical effects from substance abuse include: paranoia, psychosis, immune deficiencies, and organ damage.
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