Air Force One casts its shadow over homes as it comes in to land in Allentown, Pennsylania with U.S. President George W. Bush aboard in this October 1, 2004 file photo. (Photo by Jason Reed/Reuters)

A masked reveller poses along the flooded St. Mark's Square during a period of seasonal high water and on the first day of carnival, in Venice February 1, 2015. (Photo by Stefano Rellandini/Reuters)

An Afghan refugee girl stands near her parents' makeshift shelter in a slum on the outskirts of Lahore January 12, 2015. (Photo by Zohra Bensemra/Reuters)

Mechanics work in the Buggy belonging to Argentina's Manuel Sisterna and Adrian Echegaray during technical verification ahead of the Dakar Rally 2015 in Buenos Aires January 1, 2015. (Photo by Enrique Marcarian/Reuters)

Masked revellers pose in St. Mark's Square during the Venice Carnival, February 7, 2015. The Venetian carnival started on January 31 and runs until February 17, forty days before Easter celebrations. (Photo by Stefano Rellandini/Reuters)

Schick Hydro and Chanel Iman get guys #NakedFaced at the Schick Hydro Barbershop at The Sports Illustrated Swim City Event on February 9, 2015 in New York City. (Photo by Ilya S. Savenok/Getty Images for Schick)

Poppet, a Bearded Collie, jumps through a hoop during an agility demonstration at a news conference for the upcoming 139th Annual Westminster Kennel Club Dog Show in New York February 12, 2015. (Photo by Shannon Stapleton/Reuters)

Models prepare backstage ahead of the Strateas.Carlucci show at Mercedes-Benz Fashion Week Australia 2015 at Carriageworks on April 13, 2015 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)