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

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)

Nick Krist makes a funny face as he and his son, Noah, 8, take a selfie before a baseball game between the Los Angeles Angels and the Minnesota Twins, Wednesday, July 22, 2015, in Anaheim, Calif. (Photo by Jae C. Hong/AP Photo)

Just Dance 2017 performance at Ubisoft E3 2016 – Day 2 at the Los Angeles Convention Center on Tuesday, June 14, 2016, in Los Angeles. (Photo by Dan Steinberg/Invision for Ubisoft/AP Images)

Convicted murderer Hector Alvarado Mazariegos, right, drops to the ground as he is hit by bullets of a Guatemala firing squad in the public cemetery at Mazatenango, June 28, 1975. His companion, Rocael Ortiz, met the same fate a few seconds later. Both were convicted of murder. (Photo by AP Photo/Anzueto)

Dogs wearing masks are seen at a main shopping area, in downtown Shanghai, China, as the country is hit by an outbreak of a new coronavirus, February 16, 2020. (Photo by Aly Song/Reuters)

N.C. Dezendorf, wife of the general manager of the Electro-Motive division of General Motors, christens the new lightweight “Aerotrain” at the company's locomotive works in La Grange, Ill. on August 22, 1955. (Photo by Edward Kitch/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)