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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).
There are more bacteria in your mouth than there are people in the world.
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.
More than 50% of American adults have oral herpes, which is commonly known as "cold sores" or "fever blisters." The herpes virus can be active on the skin surface without showing any signs or causing any symptoms.
Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.