Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
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Every human spent about half an hour as a single cell.
144
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Yawns are more contagious among people with closer relationships.
163
On average, there's 100 billion neurons in the human brain.
83
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
One human hair can support 3 ounces.
191
It has been scientifically proven that stroking a cat can lower one's blood pressure!
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