|
|
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).
Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).
Your heart beats over 36 million times a year.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.