Ask unlimited questions for free
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
There are more sensory neurons in the tongue than in any other part of the body.
The B-complex vitamins and vitamin C are not stored in the body and must be replaced each day.
Cyanide works by making the human body unable to use oxygen.
For a complete list of videos, visit our video library