One out of 20 people have an extra rib.
66
A sneeze can travel as fast as 100 miles per hour.
43
Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
Enamel is hardest substance in the human body.
61
A person infected with the SARS virus, has a 95-98% chance of recovery.
23
The average sperm cell swims at 8 inches per hour.
76
A person can live without food for about a month, but only about a week without water.
156