|
|
The horizontal fraction bar was introduced by the Arabs.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.
Eating carrots will improve your eyesight. Carrots are high in vitamin A (retinol), which is essential for good vision. It can also be found in milk, cheese, egg yolks, and liver.