ANDERSEN AIR FORCE BASE, Guam - Senior Airman Billy Graves, 36th Civil Engineer Squadron entomologist, tightens his hood during a chemical, biological, radiological, nuclear, and (high-yield) explosives training course in conjunction with a field training exercise at Andersen South training facility June 3. Once the Airmen put on their MOPP 4 gear, instructors inspected them to ensure they were properly wearing their protective clothing. (U.S. Air Force photo/Airman 1st Class Courtney Witt)