|
|
Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.
In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.
The horizontal fraction bar was introduced by the Arabs.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.