Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925

A Russian prisoner eating bread. (Photo by Hulton Archive/Getty Images). Finland, circa 1940

A dog groomer prepares a model dog during the 2nd Annual Shenzhen International Pet Exhibition, July 14, 2016, in Shenzhen, China. The pet exhibition runs from July 14 - 17, 2016 at the Shenzhen Convention & Exhibition Center. (Photo by VCG/Getty Images)

Supporters of the presidential candidate Muhammadu Buhari and his All Progressive Congress hits another supporter with a motorbike during celebrations in Kano, Nigeria March 31, 2015. (Photo by Goran Tomasevic/Reuters)

A massive positive cloud-to-ground lightning strike hits in Coolidge, Arizona, 31 August 2016. Thousands of rain drops merge to form mammoth travelling sheets of water in these breathtaking monsoons. Veteran storm chaser and photographer Mike Olbinski captured the stunning beauty of monsoons in timelapses and stills while chasing storm systems across America. (Photo by Mike Olbinski/Barcroft Images)

A woman sells chips in Abidjan, Ivory Coast on August 09, 2019. World's number one cacao producer Ivory Coast's capital Abidjan set peace after the 201011 Ivorian crisis. Women in Abidjan work in various jobs to help their families' budget. (Photo by Mahmut Serdar Alakus/Anadolu Agency via Getty Images)

A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)