Ask unlimited questions for free
People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
For a complete list of videos, visit our video library