Question 1
Question 2
Ask unlimited questions for free
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
The people with the highest levels of LDL are Mexican American males and non-Hispanic black females.
Blood is approximately twice as thick as water because of the cells and other components found in it.
More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.
For a complete list of videos, visit our video library