We rarely think about how interesting and unique our bodies are. Did you know, for example, that no human being has truly black eyes? Or that if the human eye was a photo camera, its resolution would be about 576 megapixels? Or that a human produces from half a quart to 1 liter of saliva every day, depending on the person. That’s enough saliva in a year to fill a bathtub! Do you still think you know your own bodies perfectly? Okay, how about this?
The only thing that makes our blood types different is… sugar, a human hair is stronger than the same diameter copper wire, our belly buttons have an entire… .