Competitors take part in the 8th annual World Gravy Wrestling Championships at the Rose n Bowl Pub in Bacup, north west England on August 31, 2015. Contestants must participate in fancy dress and wrestle in a pool of Lancashire Gravy for 2 minutes whilst being scored for a variety of wrestling moves. (Photo by Oli Scarff/AFP Photo)

New York City policemen tangled with demonstrators at a subway station on the opening day of the New York World's Fair, April 22, 1964. Youths attempted to stall the train, which was headed from the city to the fairgrounds, as a form of protest on behalf of civil rights for blacks. (Photo by Charles Gorry/AP Photo)

A Ukrainian serviceman wearing a new year's hat waves at his comrades while standing beside his tank near Debaltseve, eastern Ukraine, February 8, 2015. (Photo by Gleb Garanich/Reuters)

Men push a motorbike through a street flooded by a river that overflowed from heavy rains caused by Hurricane Matthew in Leogane, Haiti, Wednesday, October 5, 2016. Rescue workers in Haiti struggled to reach cutoff towns and learn the full extent of the death and destruction caused by Hurricane Matthew as the storm began battering the Bahamas on Wednesday and triggered large-scale evacuations along the U.S. East Coast. (Photo by Dieu Nalio Chery/AP Photo)

A male deer barks at dawn during the annual deer rutting season at Richmond Park in London, Britain, October 9, 2016. (Photo by Toby Melville/Reuters)

A Vietnamese bride is seen pushing the groom on a scooter during a photo shoot for their wedding in An Bang Beach outside Hoi An in Vietnam December 11, 2016. (Photo by Reuters/Stringer)

A passenger inter-island ferry Shuttle RoRo 5 is pictured after it was swept ashore at the height of Typhoon Nock-Ten in Mabini, Batangas in the Philippines December 26, 2016. (Photo by Erik De Castro/Reuters)

A child plays the ice slide at the Ice-Snow World park in Harbin, capital of northeast China's Heilongjiang Province, January 5, 2017. The theme park which used about 330,000 cubic meters of ice and snow for construction opened on Thursday. (Photo by Xinhua/Barcroft Images)