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The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Approximately 500,000 babies are born each year in the United States to teenage mothers.
More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
Most women experience menopause in their 50s. However, in 1994, an Italian woman gave birth to a baby boy when she was 61 years old.
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