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The horizontal fraction bar was introduced by the Arabs.
A strange skin disease referred to as Morgellons has occurred in the southern United States and in California. Symptoms include slowly healing sores, joint pain, persistent fatigue, and a sensation of things crawling through the skin. Another symptom is strange-looking, threadlike extrusions coming out of the skin.
The human body produces and destroys 15 million blood cells every second.
Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.