Question 1
Question 2
Ask unlimited questions for free
There are 20 feet of blood vessels in each square inch of human skin.
There are more bacteria in your mouth than there are people in the world.
People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.
The longest a person has survived after a heart transplant is 24 years.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
For a complete list of videos, visit our video library