By weight, Bone is five times stronger than steel.
417
Wearing headphones for an hour increases the bacteria in your ear 700 times.
233
Although African-Americans make up only 13% of the U.S. population, they accounted for one half of the estimated new HIV/AIDS diagnoses in 2004.
70
When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23
When you look up at the blue sky and see white dots flying around, you’re actually seeing your own white blood cells.
30
The average sperm cell swims at 8 inches per hour.
4
Human teeth are almost as hard as rocks!
47
