Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

A man walks past a stranded public transport bus on a road flooded by heavy rains in Mumbai, India, August 5, 2016. (Photo by Shailesh Andrade/Reuters)

A towel with a print of the Nigerian naira is displayed for sale at a street market in the central business district in Nigeria's commercial capital Lagos February 4, 2016. (Photo by Akintunde Akinleye/Reuters)

“Entwined Lives”. Tim Laman, US Winner, Wildlife photographer of the year. A young male orangutan makes the 30-metre climb up the thickest root of the strangler fig high above the canopy in Gunung Palung national park, one of the few protected orangutan strongholds in Indonesian Borneo. Laman had to do three days of climbing to position several GoPro cameras that he could trigger remotely. This shot was the one he had long visualised, looking down on the orangutan within its forest home. (Photo by Tim Laman/2016 Wildlife Photographer of the Year)

People perform during this year's flashmob of silly walks, based on the sketch from the television show Monty Python's Flying Circus by Monty Python troup, in Budapest, Hungary, 01 April 2019. (Photo by Zoltán Balogh/EPA/EFE)

Drinking from a helmet at a graduation ceremony held by the Military University of the Russian Defence Ministry at Moscow's Victory Park in Moscow, Russia on June 15, 2019. (Photo by Gavriil Grigorov/TASS)

Russia's Dina Averina competes in the ball event of the rhythmic gymnastics individual final at the 2019 European Games in Minsk on June 23, 2019. (Photo by Kirill Kudryavtsev/AFP Photo)