Teaching others
Master Sgt. Rico Walker teaches a class on cardiopulmonary resuscitation with the Air Force Reserve. Cardio refers to the heart, while pulmonary refers to the lungs. CPR is a manual life support system that delivers oxygen to the brain, heart and other vital organs. Without this oxygen a person will die and Sergeant Walker demonstrated the proper techniques to save a life. (U.S. Air Force photo/Maj. Stan Paregien)