Students at the Cuba's National Ballet School (ENB) watch a class from outside the classroom in Havana, Cuba, October 12, 2016. Catherine Conley, the first American full-time student at Cuba's prestigious National Ballet School, hopes to gain an edge back home by learning the powerful Cuban style with its dazzling turns and jumps. (Photo by Alexandre Meneghini/Reuters)

Aeroflot employees with a puppy at the canine service of Aeroflot at Sheremetyevo International Airport in Moscow Region, Russia on October 2, 2020, that has started to train service dogs to detect COVID-19 in people. (Photo by Vladimir Gerdo/TASS)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Lazar and his sister Andjelka sit by a candle in their home in the eastern Serbian town of Majdanpek, December 4, 2014. Electricity workers in Serbia struggled through snow, ice and treacherous terrain on Thursday to restore electricity to an eastern town left shivering without power, heating or running water for a fourth day. (Photo by Marko Djurica/Reuters)

More than 400 people stripped off and ran into freezing waters to celebrate the autumn equinox – and raise money for charity at Druridge Bay, Britain, September 25, 2016. It was the largest turnout the North East Skinny Dip has ever seen in its five-year history, and it was also the first time it has ever rained on the morning of the event. Revellers gathered from 5.30am on Sunday at Druridge Bay, in Northumberland, before baring all in the North Sea. (Photo by David Charlton Photography)

Wang Zeyu, 4, a fee-paying enthusiast of kung fu, practises during a training class at a kung fu school near the Shaolin Temple April 10, 2005 in Dengfeng, Henan Province, China. Zeyu's father sent him to the school from his home in Jiangsu Province, thousands kilometres away from Dengfeng, when he was just 3 years old. And his father must pay 9,800 yuan (US$1195) for one year's tuition at the school, a huge amount for most Chinese. There are more than 80 kung fu schools that line the road from the city of Dengfeng to the Shaolin Temple with hundreds and thousands of young kung-fu lovers from all over the country and beyond studying here. All the schools use the Shaolin name to attract students as the Shaolin Temple is the birthplace of Chinese Kung Fu. (Photo by Cancan Chu/Getty Images)

A Belarusian law enforcement officer approaches women, who react while sitting on the pavement during a rally of opposition supporters following the presidential election in Minsk, Belarus on August 10, 2020. Belarusian police clashed with protesters on Monday after the opposition accused President Alexander Lukashenko of rigging his re-election victory amid a chorus of criticism from Western leaders. (Photo by Vasily Fedosenko/Reuters)