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)

One of two 9-month old Cheetahs is seen after it was released into a quarantine facility at Zoo Miami on November 29, 2012 in Miami, Florida. The two sub-adult brothers who arrived today were captive-born on March 6th of this year at the Ann van Dyk Cheetah Centre just outside of Pretoria, South Africa. The Cheetahs, after being monitored and examined for a minimum of 30 days to insure that they are healthy and stable, will be featured in Zoo Miami's Wildlife Show at the newly constructed amphitheater and will continue the work of Zoo Miami's Cheetah Ambassador Program by making appearances off Zoo grounds at a variety of venues including schools and civic organizations. (Photo by Joe Raedle)

Jeremy Davis (L) demonstrates the operation of the safe room shelter door lock to homeowner Rob Hamlin on June 18, 2011 in Neosho, Missouri. Once thought of as a luxury item there has been a surge of interest from homeowners in purchasing shelters to ride out damaging storms ever since a F5 tornado tore through the town of Joplin, Missouri. Ranging in price from $3,000 to $5,000 homeowners can supplement the cost with a mortgage insurance program offered by the U.S. Department of Housing and Urban Development for installing a safe room built to FEMA specifications. Lawmakers in Alabama have even considered requiring construction of storm shelters in mobile home parks after forty people died in April. (Photo by Julie Denesha/Getty Images)

Nimbus, the 2 month old clouded leopard cub, who was hand reared at the home of curator Jamie Craig. Photographed sitting in her hammock at Cotswold Wildlife Park, Burford, Oxfordshire, UK on September 2014. Jamie Craig the curator of the Cotswold Wildlife park has hand reared the baby clouded leopard in his family bathroom after he was rejected by his mother. Now two months old Nimbus is been fed a cat milk replacement diet by bottle and is given soft toys to play with. It is hoped that the leopard will re-join others at the park and eventually join their breeding program. (Photo by SWNS/ABACAPress)

Members of a historical re-enactment group dressed as U.S. and Soviet Army soldiers take part in Elbe Day celebrations, in eastern German city of Torgau at the river Elbe, April 25, 2015. Elbe Day commemorates the encounter of the Allies 70 years ago, on the 25th of April 1945 when American and Soviet army units joined together on the destroyed bridge over the river Elbe. The photograph of the meaningful handshake made its way around the world and became a symbol of the near end of World War II in Europe. (Photo by Stefanie Loos/Reuters)

Mexicans dressed as French soldiers carry handcrafted guns, ahead of a reenactment of the battle of Puebla between Zacapoaxtla Indians and the French army during Cinco de Mayo celebrations in Mexico City, Tuesday, May 5, 2015. Monsalvo said he has been portraying Napoleon III in the annual neighborhood event for 28 years. Cinco de Mayo commemorates the victory of an ill-equipped Mexican army over French troops in Puebla on May 5, 1862. (Photo by Rebecca Blackwell/AP Photo)

Residents recently returning to their area cleared by government troops react as they ride a tricycle a day after President Rodrigo Duterte declared the liberation of Marawi city in southern Philippines Wednesday, October 18, 2017. Sporadic explosions continue Wednesday as Philippine soldiers fought to gain control of the last pocket of Marawi controlled by Islamic militants. (Photo by Bullit Marquez/AP Photo)

A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)