A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela' s angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro' s plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Juan Barreto/AFP Photo)

Chinese soldiers leave after Chinese President Xi Jinping inspected troops of People's Liberation Army (PLA) Hong Kong Garrison at the Shek Kong Barracks in Hong Kong, Friday, June 30, 2017. Xi landed in Hong Kong Thursday to mark the 20th anniversary of Beijing taking control of the former British colony, accompanied by a formidable layer of security as authorities showed little patience for pro-democracy protests. (Photo by Kin Cheung/AP Photo)

Social distancing signs are pictured as models wear protective face masks before the show of designer Andres Sarda during the Mercedes Benz Fashion Week amid the coronavirus disease (COVID-19) outbreak in Madrid, Spain, September 10, 2020. (Photo by Sergio Perez/Reuters)

Pupils wearing face masks wait for the opening of their primary school on the first day of the new school year, in Ouagadougou, on October 1, 2020. (Photo by Olympia de Maismont/AFP Photo)

Inbar Regev, an eight-year-old Israeli girl, holds her pet python while swimming in her backyard pool in Ge'a, southern Israel on October 7, 2020. (Photo by Amir Cohen/Reuters)

Police officers look on as protesters block the road with burning tyres and wood, during a mass protest the morning after preliminary results were released for five communes in Conakry on October 21, 2020. African monitors said on October 20, 2020, that Guinea's weekend election was conducted properly, but the political opposition to incumbent Alpha Conde, which has already claimed victory, dismissed it as fraudulent. (Photo by John Wessels/AFP Photo)

Members of the media touch a moving model of a Tyrannosaurus, which uses a dinosaur-type human-operated mechanical suit called “Dino-Techne” by Japanese firm On-Art, during a media preview of the Dinoa Live Exhibition / Amazing Dinosaur Art Exhibition in the Shinjuku district of Tokyo on December 10, 2020. (Photo by Philip Fong/AFP Photo)

Mahmoud El Komy, a 26-year-old Egyptian mechatronics engineer, stands beside Cira 3, a remote-controlled robot that runs tests on suspected coronavirus disease (COVID-19) patients, to limit the human exposure to the virus, amid a second wave of infections in Tanta, Egypt, November 18, 2020. (Photo by Mohamed Abd El Ghany/Reuters)