|
|
Did you know?
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Did you know?
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Did you know?
Thyroid conditions may make getting pregnant impossible.
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?
The horizontal fraction bar was introduced by the Arabs.