U.S. Marines complete paperwork upon arrival at Langley Transit Center at Langley Air Force Base, Va., Nov. 13, 2014. The Marines were among 90 service members who will undergo a 21-day controlled monitoring period at the transit center following their return from fighting the spread of Ebola in West Africa as part of Operation United Assistance. (U.S. Air Force photo by Staff Sgt. Jason J. Brown/Released)