A street artist dances tango in Buenos Aires, Argentina, Tuesday, January 20, 2015. Tango is a partner dance that originated in the 1890's along the Rio de la Plata, the border between Uruguay and Argentina. UNESCO approved in 2009, a joint proposal by the two nations to include the dance in its Intangible Cultural Heritage List. (Photo by Rodrigo Abd/AP Photo)

Vehicles and weapons of the Justice and Equality Movement (JEM) rebels are seen on display, after victory celebrations by the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF), in Niyala Capital of South Darfur, May 4, 2015. (Photo by Reuters/Stringer)

U.S. Air Force wounded warrior, Capt. Sarah Evans, jumps rope in a gym in San Antonio, Texas. Evans was diagnosed with cancer while deployed to Afghanistan and was medically evacuated back to the United States where her leg was amputated. (Photo by Master Sgt. Jeffrey Allen/U.S. Air Force)

Tokyo, “Electric City”. August 24, 2009. (Photo by Caribb; Source: Flickr)

A man rides a horse through a bonfire on January 16, 2009 in the small village of San Bartolome de Pinares, Spain. In honor of San Anton, the patron saint of animals, horses are riden trough the bonfires on the night before the official day of honoring animals in Spain. (Photo by Denis Doyle/Getty Images)

Christie's employee Natalie McFarlane holds an armature model of King Kong used in the 1933 film at Christie's on November 19, 2009 in London. (Photo by Peter Macdiarmid/Getty Images)

A Border Collie competes in the Flyball during The World Dog Games at Acer Arena on October 31, 2009 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

Mr. Ben, a pygmy slow loris, is administed anesthetic during one of Bristol Zoo's in-house veterinary clinic routine health check-up and teeth clean as part of the Zoo's standard animal husbandry and welfare procedure at Bristol Zoo on June 18, 2009 in Bristol, England. (Photo by Matt Cardy/Getty Images)