A police officer chases shoppers to clear the streets of the Red Light market on the first day of lockdown to stop the spread of the coronavirus disease (COVID-19) in Monrovia, Liberia on April 11, 2020. (Photo by Derick Snyder/Reuters)

A four-legged robot dog called SPOT patrols a park as it undergoes testing to be deployed as a safe distancing ambassador, following the coronavirus disease (COVID-19) outbreak, in Singapore on May 8, 2020. (Photo by Edgar Su/Reuters)

This photo taken on May 20, 2020 shows elementary school students wearing wings to maintain social distancing amid concerns of the COVID-19 coronavirus, in a classroom in Taiyuan in China's northern Shanxi province. (Photo by AFP Photo/China Stringer Network)

The body of one of several U.S. soldiers who were executed after being captured by North Korean troops just south of Seoul in early July 1950. (Photo by AP Photo)

Police detain a woman protesting against the court verdict for Yuliy Boyarshinov, and Viktor Filinkov, members of a left-wing group Set (Network) at the Western regional military court in St.Petersburg, Russia, Monday, June 22, 2020. A Russian military court convicted two members of a left-wing youth group of terrorism Monday and sentenced them to prison terms of five and a half and seven years, in a case that human rights groups called fabricated and based on coerced testimony. (Photo by Dmitri Lovetsky/AP Photo)

North Korean youngsters sing and play accordions to entertain foreign visitors including United Nations Secretary General Kurt Waldheim, who visited Pyongyang, May 4, 1979. Visitors report music education in North Korea begins at an early age and is taken seriously by children and adults. (Photo by Peter Arnett/AP Photo)

A picture shows the full moon during a “blood moon” eclipse over the temple of Apollo in Corinth on July 27, 2018. The longest “blood moon” eclipse this century began on July 27, coinciding with Mars' closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle. (Photo by Valerie Gache/AFP Photo)

Chilean police officers march with the puppies of future police dogs during the annual military parade at the Bernardo O'Higgins park in Santiago, Chile, September 19, 2018. (Photo by Rodrigo Garrido/Reuters)