Ask unlimited questions for free
The horizontal fraction bar was introduced by the Arabs.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
Approximately 70% of expectant mothers report experiencing some symptoms of morning sickness during the first trimester of pregnancy.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
There are more bacteria in your mouth than there are people in the world.
For a complete list of videos, visit our video library