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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.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.
Vaccines prevent between 2.5 and 4 million deaths every year.
On average, the stomach produces 2 L of hydrochloric acid per day.
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