Question 1
Question 2
Ask unlimited questions for free
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.
The familiar sounds of your heart are made by the heart's valves as they open and close.
There are more nerve cells in one human brain than there are stars in the Milky Way.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
For a complete list of videos, visit our video library