A group of students sit on top of a bus at Kemusu street in Boyolali, Central Java of Indonesia, March 20, 2015 in this picture taken by Antara Foto. (Photo by Yusuf Nugroho/Reuters/Antara Foto)

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)

The beard of a skater, one out of some 1,100 athletes, is covered with ice and snow during the 200 km (124 miles) speed skating race in the Carinthian village of Techendorf January 30, 2015. Techendorf is hosting the Alternatieve Elfstedentocht Weissensee (Alternative Eleven City Races Weissensee) races, a traditional Dutch series of speed skating events for both professionals and amateurs with some 5,000 participants, until January 31, 2015. (Photo by Leonhard Foeger/Reuters)

A female Indian rhinoceros called Maruska eats a vegetable birthday cake on her first birthday celebration at the Plzen Zoo on February 3, 2015 in Plzen, Czech Republic. (Photo by Ladislav Nemec/Isifa)

Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

“Nature is beautiful and amazing – i just point my camera at it”. – Black Cat. Photo: “I really need a manicure”! (Photo by Black Cat)

A Tampa Bay Buccaneers cheerleader, wear a military-inspired outfit as part of the NFL's Salute to Service program, flips her hair during a game between the Buccaneers and San Diego Chargers in Tampa, on November 11, 2012. (Photo by Phelan M. Ebenhack/Associated Press)