A Chesterfield Borough Police telephone operator tests a gasmask with built in earpiece and microphone. The telephone service is considered one of the most important links in the coordination of ARP operations and must remain operational during air raids, 12th April 1939. (Photo by Fox Photos/Hulton Archive/Getty Images)

The Greyfriars Bobby statue is pictured wearing a mask as the spread of the coronavirus disease (COVID-19) continues, in Edinburgh, Scotland, Britain, March 23, 2020. (Photo by Russell Cheyne/Reuters)

A devotee, dressed as Hindu God Shiva, looks out from a window as he waits to perform during the annual Shiva Gajan religious festival on the outskirts of Agartala, India April 13, 2018. (Photo by Jayanta Dey/Reuters)

A model is seen backstage before the Spring/Summer 2019 women's ready-to-wear collection show for Y-Vision X Jessie & Jane during Paris Fashion Week in Paris, France, October 1, 2018. (Photo by Stephane Mahe/Reuters)

North Korean bodyguards run along a limousine transporting Kim Jong Un upon his arrival in Dong Dang, Vietnam, February 26, 2019. The second meeting of the US President and the North Korean leader, running from 27 to 28 February 2019, focuses on furthering steps towards achieving peace and complete denuclearization of the Korean peninsula. (Photo by Reuters/Stringer)

Swiss grass skier Stefan Portmann in action during a free practice at the Grasski World Championships in Marbach, Switzerland, 13 August 2019. About 80 participants from 10 nations will start at the Grasski - World Championships, which will take place from 13th to 18th August 2019. (Photo by Alexandra Wey/EPA/EFE)

A Naga girl carries a child and walks up a slope during sunset in Kohima, capital of the northeastern Indian state of Nagaland, Thursday, September 19, 2019. Nagas are indigenous people living in several northeastern Indian states and across the border in Myanmar. (Photo by Yirmiyan Arthur/AP Photo)

A young girl taking part in a hairdressing contest during the 5th Abilympics Russia vocational skills championship for people with disabilities, at Moscow's VDNKh exhibition centre in Moscow, Russia on November 21, 2019. The competition is aimed at ensuring social adaptation and job opportunities for people with disabilities. (Photo by Valery Sharifulin/TASS)