U.S. Marines assigned to Bravo Battery, 2nd Low Altitude Air Defense Battalion, link chains to a Motor Transport Vehicle Replacement 7-ton truck during field training exercise No Easy Day at Camp Lejeune, N.C., Feb. 6, 2015. The exercise was conducted to test and increase the Marine's efficiency and ability to engage an enemy aircraft. (U.S. Marine Corps photo by Lance Cpl. Koby I. Saunders/Released)