A performer from Cirque du Soleil's show “Quidam” practices backstage before a show at the MEO Arena in Lisbon December 18, 2014. (Photo by Rafael Marchante/Reuters)

A Lockheed Super Constellation “Super Connie” lands during the Air14 airshow at the airport in Payerne August 30, 2014. The Swiss Air Force celebrates their 100th anniversary with the biggest airshow in Europe this year. (Photo by Ruben Sprich/Reuters)

Jeff and Kelly Lyons clear the first obstacle while competing in the North American Wife Carrying Championship at Sunday River ski resort in Newry, Maine October 11, 2014. (Photo by Brian Snyder/Reuters)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

A visitor poses with artist Joyce Pensato's artwork “Mickey for Micky” at the Frieze Art Fair in London, October 14, 2014. (Photo by Luke MacGregor/Reuters)

A visitor visit the “12 Labors of Putin” art exhibition on October 6, 2014 marking the 60th birthday of Russia's President Vladimir Putin at the design workshop in Moscow. (Photo by Vasily Maximov/AFP Photo)

Ice covered leafs are pictured on a tree near Amstall in northern Austria, December 2, 2014. Freezing fog and rain covered parts of the region with ice, causing blocked roads due to fallen trees and closed schools for security reasons, local media report. (Photo by Heinz-Peter Bader/Reuters)

A gallery assistant poses with the 1972 work “Secretary” at a press viewing of the artist's exhibition “Allen Jones RA” at the Royal Academy of Arts in London November 11, 2014. (Photo by Neil Hall/Reuters)