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)

Bronze whaler shark (Carcharhinus brachyurus), caught in traditional seine net and released by fisherman, Muizenberg beach, Cape Town, South Africa on October 11, 2016. Action shots have captured fishermen trying to free a potentially deadly Bronze Whaler shark who was caught in their nets. The incredible images show the eight-foot-long 500-pound predator lunging its mouth towards the fishermen who are desperately trying to pull it back into the safety of the sea by its tail. Eventually they succeeded. (Photo by Chris and Monique Fallows/NPL)

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)

Hamish the polar bear tries out his new enclosure at the Yorkshire Wildlife Park at Branton, Doncaster on November 6, 2020, after moving from the Highland Wildlife Park in Scotland. Hamish was the first polar bear to be born in the UK. (Photo by Danny Lawson/PA Wire Press Association)

People walk through Manhattan in a snow storm on December 16, 2020 in New York City. New York City is expected to get between 10 inches and a foot of snow on Wednesday and Thursday in what is the first winter storm of the year. (Photo by Spencer Platt/Getty Images)

Volunteers of a Wild Nature Preservation center release a group of owl chicks from the Toro Mountain in Menorca, Balearic Islands, Spain, 31 July 2019. (Photo by David Arquimbau Sintes/EPA/EFE/Rex Features/Shutterstock)

A transparent van is displayed by a vendor for safety devices at the IAA Auto Show in Frankfurt, Germany, Tuesday, September 10, 2019. (Photo by Michael Probst/AP Photo)

A Citroen Ami One concept car sits on display during the media day of the Auto Shanghai 2019 motor show in Shanghai, China, 16 April 2019. The 18th Shanghai international automobile industry exhibition runs from 16 to 25 April. (Photo by Wu Hong/EPA/EFE)