Su Daocheng rides his home-made mechanical horse vehicle on a street in Shiyan, Hubei province January 18, 2015. Su spent 2 months making this 1.5 metre high and 2 metre long horse, which weighed 250 kilograms with 4 legs and 2 supportive wheels, local media reported. (Photo by Reuters/Stringer)

An Afghan journalist takes a “selfie” as U.S. President Barack Obama (R) holds a joint news conference with Afghanistan's President Ashraf Ghani (C) at the White House in Washington March 24, 2015. (Photo by Jonathan Ernst/Reuters)

Andrea Petkovic of Germany in action against Sara Errani of Italy during day one of the Mutua Madrid Open tennis tournament at the Caja Magica on May 3, 2014 in Madrid, Spain. (Photo by Julian Finney/Getty Images)

Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)

Wearing traditional Belarus costumes girls jump over a bonfire as they celebrate the Ivan Kupala night, an ancient heathen holiday, held in the countryside near the town of Turov, some 260 km southwest of the capital Minsk, on July 6, 2014. People celebrate Kupala Night with bonfires that last throughout the night with some leaping over the flames as it is believed that the act of jumping over the bonfire cleanses people of illness and bad luck. (Photo by Viktor Drachev/AFP Photo)

A woman offers prayers by a road as a rickshaw puller transports passengers in Kolkata October 28, 2014. (Photo by Rupak De Chowdhuri/Reuters)

(L-R) Poppy Delevingne, Model of the Year Cara Delevingne, Joan Smalls and Karlie Kloss pose in the winners room at the British Fashion Awards at London Coliseum on December 1, 2014 in London, England. (Photo by Pascal Le Segretain/Getty Images)

A woman participates in the “Carnaval na Central” block party in Rio. (Photo by Felipe Dana/Associated Press)