Ask unlimited questions for free
Approximately 500,000 babies are born each year in the United States to teenage mothers.
In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.
The familiar sounds of your heart are made by the heart's valves as they open and close.
In 1844, Charles Goodyear obtained the first patent for a rubber condom.
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.
For a complete list of videos, visit our video library