Ask unlimited questions for free
A seasonal flu vaccine is the best way to reduce the chances you will get seasonal influenza and spread it to others.
Aspirin is the most widely used drug in the world. It has even been recognized as such by the Guinness Book of World Records.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
About 600,000 particles of skin are shed every hour by each human. If you live to age 70 years, you have shed 105 pounds of dead skin.
The longest a person has survived after a heart transplant is 24 years.
For a complete list of videos, visit our video library