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Author Question: By about eighteen months of age, children show some knowledge of gender categories by a. ... (Read 58 times) |
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.
In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.
Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.
Increased intake of vitamin D has been shown to reduce fractures up to 25% in older people.