Multiple choice Why should we keep a handkerchief on the nose and mouth while sneezing? It prevents the growth of microorganism It presents breeding of microorganism in air It prevents spread of micro organisms in the air It promotes growth of microorganism Reveal answer Fill a bubble to check yourself C Correct answer Explanation Communicable diseases may spread from a diseased to a healthy person through air, water or food. When we sneeze, we release micro organisms into air. If they are disease-causing, they will infect the other person also.