Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

Russian soldiers from 34th motorized infantry mountain brigade, 58th Army, prepare to evacuate a fellow soldier acting as an injured person during a drill at the Darial range outside Russia's city of Vladikavkaz, July 28, 2010. (Photo by Kazbek Basayev/Reuters)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

A man wearing a mask and dressed in a clown costume rides an electric tricycle while carrying a container in the shape of a rubber duck amid heavy smog in Beijing, China, December 29, 2015. (Photo by Jason Lee/Reuters)

In this April 20, 2018, file aerial photo released by China's Xinhua News Agency, advection fog drifts across skyscrapers on the waterfront in Qingdao in eastern China's Shandong Province. Chinese leaders have long been sensitive about their communist country’s international image. Now, they are battling back, investing in diplomacy and a courtship of hearts and minds, just as the United States digs in on the Trump administration’s “America First” mindset. (Photo by Lu Hui/Xinhua via AP Photo/File)

WWII veterans attend a ceremony to place tobacco pouches of soil from WWII mass graves of Red Army soldiers abroad, in the custody of the Central Armed Forces Museum in Moscow, Russia on March 6, 2020. The grave soil has been brought from Abkhazia, Germany, Kyrgyzstan, US, Ukraine, France, Estonia, Mongolia, Bulgaria, UK, Uzbekistan and South Ossetia. (Photo by Alexander Shcherbak/TASS)

A woman who was injured after being trampled is helped away, after residents desperate for a planned distribution of food for those suffering under Kenya's coronavirus-related movement restrictions pushed through a gate and created a stampede, causing police to fire tear gas and leaving several injured, at a district office in the Kibera slum, or informal settlement, of Nairobi, Friday, April 10, 2020. (Photo by Brian Inganga/AP Photo)