Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
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Medication errors are three times higher among children and infants than with adults.
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Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
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The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
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The eye muscles are the most active muscles in the whole body. The external muscles that move the eyes are the strongest muscles in the human body for the job they have to do. They are 100 times more powerful than they need to be.
Glaucoma. (a) A buildup of pressure within the eye cavities, often caused by a blockage of vessels t
The steps in the hearing process. (1) Sound waves enter the outer ear and travel through the ear ...