Visitors and a dog stand on the new “Skywalk” viewing platform on the Sonnenstein mountain in the Eichsfeld region near Bad Lauterberg im Harz, central Germany, on May 22, 2017. (Photo by Martin Schutt/AFP Photo/DPA)

Engineer Thomas Dwyer stands with the new Bionic Exoskeleton next to Amanda Boxtel during its launch at the Excel centre on October 21, 2011 in London, England. The bionic device developed by Ekso Bionics is a wearable, battery-powered, robotic exoskeleton, designed to aid wheelchair users and those who have suffered from spinal chord injuries to stand and walk. (Photo by Dan Kitwood/Getty Images)

Pro-government fighters stand next to a tank destroyed during recent fighting in Yemen's southwestern city of Taiz March 14, 2016. (Photo by Anees Mahyoub/Reuters)

A woman dressed as a character from the computer game “World of Warcraft” stands in a forest near the village of Sosnova, Czech Republic, April 30, 2016. (Photo by David W. Cerny/Reuters)

A Ukrainian serviceman wearing a new year's hat waves at his comrades while standing beside his tank near Debaltseve, eastern Ukraine, February 8, 2015. (Photo by Gleb Garanich/Reuters)

School girls stand next to a ballot box at a polling station during the municipal elections in Havana April 19, 2015. Cuba held its first local elections since a historic thaw in relations with the United States with an unusual wrinkle in the single-party system: two of the 27,000 candidates openly oppose the government. (Photo by Reuters/Stringer)

People stand with sheep for sacrifice outside a church during St. George's Day celebration in the village of Ikalto, Georgia, November 23, 2015. Georgia marks on Monday one of its most popular religious and public holidays. (Photo by David Mdzinarishvili/Reuters)