books.google.com - • What time is it at the North Pole? • What's the chemical formula for a human being? • Why do boomerangs come back? • Why do flying fish fly? • Do the living really outnumber the dead? • Why does lightning fork? • Why does the end of a whip crack? Everyone has at one time...https://books.google.com/books/about/Why_Don_t_Penguins_Feet_Freeze.html?id=Egp3tWYDTxoC&q=hard+water&utm_source=gb-gplus-shareWhy Don't Penguins' Feet Freeze?