|
|
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.
It is widely believed that giving a daily oral dose of aspirin to heart attack patients improves their chances of survival because the aspirin blocks the formation of new blood clots.
The highest suicide rate in the United States is among people ages 65 years and older. Almost 15% of people in this age group commit suicide every year.
![Illustration showing how the primary breast tumor metastasized through the lymphatic and blood vesse](https://biology-forums.com/gallery/47/medium_14755_27_08_12_12_17_41_8191646.jpeg)
![Age-related changes in crystallized and fluid tasks. Performance on tests of fluid abilities peaked ...](https://biology-forums.com/gallery/27/medium_660366_07_04_17_9_55_37_274801249.jpeg)