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)

Artist Emiliano Paolini (R), and his partner Marianela Perelli, show their “Ken” doll that they have re-designed into the religious figure of Jesus Christ at their workshop in Rosario, north of Buenos Aires September 23, 2014. Paolini and Perelli have adapted religious figures such as Jesus Christ, Moses and the Virgin of Guadalupe to Mattel's line of Barbie and Ken dolls and are working on more religious figures, although they say they will not be using the Prophet Muhammad to avoid controversy. They plan to have a gallery show in Buenos Aires next October. (Photo by Enrique Marcarian/Reuters)

Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

France's Alize Cornet celebrates scoring a point in the first round match of the French Open tennis tournament against Italy's Roberta Vinci at the Roland Garros stadium, in Paris, France, Monday, May 25, 2015. (Photo by Christophe Ena/AP Photo)

Locals sort through garbage at a roadside dump in New Delhi on January 10, 2017 The national capital has been reeling under tonnes of garbage after sanitation workers went on a strike demanding payment of pending salaries. (Photo by Chandan Khanna/AFP Photo)

Chinese paramilitary guards monitoring passengers as they head to their train to travel to their hometowns for the “Spring Festival” or Lunar New Year at Nantong Railway Station in Jiangsu province, near Shanghai Travellers taking part in the world' s largest annual human migration must be home by January 27 to usher in the new year on January 28. (Photo by AFP Photo/Stringer)

A worker fills a public bus with diesel as the bus driver and passengers look on, at a fuel station in Kolkata, India, February 1, 2017. (Photo by Rupak De Chowdhuri/Reuters)