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Did you know?
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
Did you know?
The B-complex vitamins and vitamin C are not stored in the body and must be replaced each day.
Did you know?
Vaccines prevent between 2.5 and 4 million deaths every year.
Did you know?
The familiar sounds of your heart are made by the heart's valves as they open and close.
Did you know?
The lipid bilayer is made of phospholipids. They are arranged in a double layer because one of their ends is attracted to water while the other is repelled by water.

