U.S. Marine Corps Lance Cpl. Mainley Ho, a rifleman with 1st Battalion, 9th Marine Regiment, prepares for a training patrol on Camp Leatherneck, Helmand province, Afghanistan, Dec. 20, 2013. The training was performed to teach the Marines to properly mark improvised explosive devices during a patrol. (Official Marine Corps Photo by Lance Cpl. Zachery B. Martin/Released)