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)

Russia's Maria Stavitskaia performs during the ladies short program at the Rostelecom Cup ISU Grand Prix of Figure Skating in Moscow November 14, 2014. (Photo by Grigory Dukor/Reuters)

A man is seen trapped amid the debris of an under-construction flyover after it collapsed in Kolkata, India, March 31, 2016. Using saws, small cranes and bare hands, rescuers on Friday cleared the crumbled concrete and twisted steel from an overpass that collapsed onto a crowded Kolkata neighborhood, killing at least 23 people and injuring more than 80. With more than half the debris cleared by Friday morning, 67 people have been pulled out alive, police said. (Photo by Rupak De Chowdhuri/Reuters)

An attendee dances at the start of the “Big Goth Dance Party” during the Porcupine Freedom Festival, or PorcFest, the Free State Project's annual summer gathering in Lancaster, NH on Wednesday, June 25, 2014. (Photo by Matthew Cavanaugh/The Washington Post)

A boy walks with toy guns as people ride an APC during a military show at the Finnish Gulf coast in St.Petersburg, Russia, Saturday, September 5, 2015. (Photo by Dmitry Lovetsky/AP Photo)

Ghanaian fans take a selfie prior to a Group G football match between Germany and Ghana at the Castelao Stadium in Fortaleza during the 2014 FIFA World Cup on June 21, 2014. (Photo by Patrik Stollarz/AFP Photo)

Women pose for a picture at the entrance of the Carlton Hotel, in the government controlled area of Aleppo, Syria December 17, 2016. (Photo by Omar Sanadiki/Reuters)

Father Christmas hands out presents to children at the Aid And Adoption Society home at Leytonstone. (Photo by Gerry Cranham/Fox Photos/Getty Images). 7th December 1938