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)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)

In this September 27, 2017 file photo, girls walk past a wall riddled with bullet holes from shootings between rival drug traffickers, at the Rocinha slum, in Rio de Janeiro, Brazil. Violence is on the rise in Rio's slums after several years of decline, and the killings of kids have shocked even residents long inured to deaths from gangs and police. (Photo by Silvia Izquierdo/AP Photo)

A Sadhu or a Hindu holy man performs to receive money from pilgrims at a makeshift shelter, before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India, January 10, 2018. (Photo by Rupak De Chowdhuri/Reuters)

Chelyabinsk Airport employees take part in an exercise to evacuate aircraft passengers showing symptoms of the 2019-nCoV pneumonia-like coronavirus on February 5, 2020. (Photo by Nail Fattakhov/TASS)

People in face masks cross a near-empty street after the government announced a state of emergency for the capital and some prefectures following the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan on April 16, 2020. (Photo by Kim Kyung-Hoon/Reuters)

A staff member, wearing a face mask following the coronavirus disease (COVID-19) outbreak, looks at a robot at the venue for the World Artificial Intelligence Conference (WAIC) in Shanghai, China on July 9, 2020. (Photo by Aly Song/Reuters)

A motor taxi driver gets his hands washed at an Ebola screening station on the road between Butembo and Goma on July 16, 2019 in Goma. The first patient to be diagnosed with Ebola in the eastern DR Congo city of Goma has died, the governor of North Kivu province said on July 16, 2019. The case – the first in a major urban hub in the region's nearly year-old epidemic of the disease – has sparked deep concern in neighbouring Rwanda and at the UN. (Photo by John Wessels/AFP Photo)