Sneezes and hiccups
Breathing normally happens so smoothly that we hardly notice it. But sometimes it is interrupted by a cough, a sneeze, or by hiccups. Hiccups happen when your diaphragm contracts suddenly and air rushes into your lungs. Your vocal cords, membranes lying across your trachea that you use to talk, close, making a loud squeak. Coughs and sneezes clear out dust and other particles that get trapped in your airways and the lining of your nose. Colds cause coughs and sneezes for a few days, smoking can give people cough for years because some of the smoke gets stuck in the lungs.

Drops of moisture, dust and germs shoot into the air when you sneezes.