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Did you know?
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
Did you know?
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Did you know?
Illicit drug use costs the United States approximately $181 billion every year.
Did you know?
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.
Did you know?
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.