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)

In this photo taken Saturday, February 14, 2015, Benjamin Miller, 20, from Georgia, in the US, is gored by a bull during the “Carnaval del Toro” in Ciudad Rodrigo, Spain. An American youth is recovering in the intensive-care unit of a hospital in western Salamanca after being savagely gored during a bullfighting festival celebrating Carnival, officials said Sunday. Surgeon Enrique Crespo said he was called to operate on 20-year-old Benjamin Miller from Georgia, who had been gored and tossed by a large fighting bull on Saturday, the first day of nearby Ciudad Rodrigo's “Carnaval del Toro”. (Photo by Jose Vicente/AP Photo)

In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

Zhao Qiang walks across a street in Shenyang, Liaoning province, April 14, 2014. Zhao, a community officer of the China Disabled Persons' Federation, was diagnosed with multiple when he was two, with the resulting tumour affecting the growth of his left leg, his grandmother told local media, citing a doctor's diagnosis. His uncle modified his shoes, fitting them with stools, to allow Zhao to stand and walk. (Photo by Reuters/Stringer)

In this Thursday, May 8, 2014 photo, guests look down from the Tilt!, a new tourist attraction that provides guests a unique view of the downtown area from the 94th floor of the John Hancock Building, after it was unveiled in Chicago. People hold onto handrails as the glass and steel facade tilts forward 30 degrees. (Photo by Ashlee Rezin/AP Photo/Sun-Times Media)

A performer presents a creation from the Haute Coiffure Fall-Winter 2014/15 collection by French designer Charlie Le Mindu during the Paris Fashion Week, in Paris, France, July 7, 2014. The presentation of the Haute Couture collections runs from 06 to 10 July. (Photo by Etienne Laurent/EPA)

Ryan Randall plays the bagpipes outside a polling station in Edinburgh, Scotland September 18, 2014. Polling in the referendum on Scottish independence began on Thursday morning, as Scotland votes whether or not to end the 307-year-old union with the rest of the United Kingdom. (Photo by Paul Hackett/Reuters)

A rider holds on as a bull tries to throw him during the Bull Ride Spectacular on the first day of the 2014 Deni Ute Muster at the Play on the Plains Festival grounds on October 3, 2014 in Deniliquin, Australia. (Photo by Mark Kolbe/Getty Images)