It takes 7 seconds for food to pass from mouth to stomach. A human hair can hold 3 kilograms. The length of a penis is three times the length of a thumb. The femur is as hard as concrete. A woman's heart beats faster than a man's. Women blink twice as often as men. We use 300 muscles just to keep our balance when we stand. A woman has read this entire text. A man is still looking at his thumb.