|
|
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
To combat osteoporosis, changes in lifestyle and diet are recommended. At-risk patients should include 1,200 to 1,500 mg of calcium daily either via dietary means or with supplements.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.