A young man with an amputated leg poses for a photograph standing by his broken artificial limb in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria March 20, 2016. Two university students forced to interrupt their studies have learnt to make and fit hundreds of new limbs in the past four years in opposition-held areas of Syria. A mobile clinic operating from a truck has gone some way to improve access to treatment. While most patients are between 15 and 45, the clinic also helps children and the elderly with replacement limbs. (Photo by Khalil Ashawi/Reuters)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)

A man stands at a passenger train damaged in a collision with a freight train in Moscow region May 20, 2014. The passenger train on its way to Moldova collided with a freight train near Moscow on Tuesday, killing at least four people and injuring 15, a spokeswoman for Russia's Emergencies Ministry said. The reason for the collision, near the town of Naro-Fominsk 55 km (34 miles) southwest of Moscow, was not immediately clear. (Photo by Grigory Dukor/Reuters)

The under-construction Shard building on December 5, 2011 in London, England. The 80 storey skyscraper will be Europe's tallest mixed-use building when it is completed in May 2012; it will contain offices, restaurants, residential apartments as well as a five star hotel. (Photo by Dan Kitwood/Getty Images)

The London 2012 ArcelorMittal Orbit Sculpture at the Olympic park nears completion on November 4, 2011 in London, England. The Ј22 million sculpture designed by Anish Kapoor is nearly complete. Standing at 115 meters tall the permanent structure is Britain's largest artwork and houses an observation deck near the top. (Photo by Peter Macdiarmid/Getty Images)

Nikolay Skidan, a hunter, carries the skin of a wolf in the village of Khrapkovo, Belarus February 1, 2017. Wolf fur grows thickest in winter, so Belarussian hunter Vladimir Krivenchik only sets his traps once snow is on the ground. He and his wife live on the edge of the Chernobyl exclusion zone – 2,600 square km of land on the Belarus-Ukraine border that was contaminated by a nuclear disaster in 1986. (Photo by Vasily Fedosenko/Reuters)

Emergency personnel respond to the scene of a train derailment in Santiago de Compostela, Spain, on Wednesday, July 24, 2013. A train derailed in northwestern Spain on Wednesday night, toppling passenger cars on their sides and leaving at least one torn open as smoke rose into the air. Dozens were feared dead, with possibly even more injured. (Photo by Antonio Hernandez/AP Photo/El correo Gallego)

Kathleen Darling, wife of disabled veteran Caleb Darling, celebrates a shot during a sled hockey game on March 29, 2012 in Aspen, Colorado. (Photo by John Moore/Getty Images)