Attendees participate in trivia at the Air Force Sergeants Association table during a Base Appreciation Day at Ellsworth Air Force Base, S.D., Sept. 16, 2017. Non-profit organizations and Airmen from both the 28th Security Forces Squadron and 28th Civil Engineer Squadron participated in the event, hosting displays and performing demonstrations. (U.S. Air Force photo by Airman 1st Class Randahl J. Jenson)