|
|
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.
Although puberty usually occurs in the early teenage years, the world's youngest parents were two Chinese children who had their first baby when they were 8 and 9 years of age.
The horizontal fraction bar was introduced by the Arabs.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
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.
![(A) In hyperopia, light rays focus behind the retina, making it difficult to focus on objects at ...](https://biology-forums.com/gallery/30/medium_548020_08_06_17_6_38_46_305761211.jpeg)
![Colored scanning electron micrograph (SEM) of a helper T cell (green) with HIV viruses (red) budding ...](https://biology-forums.com/gallery/30/medium_548020_08_06_17_10_08_21_30635578.jpeg)