Ants will never cross a white line on a football field. They are allergic to the white chalk. Each sugar crystal has 16 sides. The Great Wall of China is the largest man made object that can bee seen from a satellite going around the earth. Hydrogen is an explosive gas.
Oxygen supports combustion.
Yet when these are combined it is water which is used to put out fires. At least you'll never go broke. Oysters make pearls from lime slime on a grain of sand.