Ask unlimited questions for free
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
The horizontal fraction bar was introduced by the Arabs.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
On average, the stomach produces 2 L of hydrochloric acid per day.
For a complete list of videos, visit our video library