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There are approximately 3 million unintended pregnancies in the United States each year.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
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