A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Antonina Yermokhina, 86, does physical exercises during her daily training session on the embankment of the Yenisei River in the Siberian town of Divnogorsk, Russia November 13, 2017. (Photo by Ilya Naymushin/Reuters)

Figure skater Alexandra Trusova of Team ROC practices during a training session at the 2022 Winter Olympic Games, at the Capital Indoor Stadium in Beijing, China on February 19, 2022. (Photo by Valery Sharifulin/TASS)

Commuters watch after their train was blocked by leftist activists at a railway station during a nationwide general strike against the policies of the central government in Kolkata on March 28, 2022. (Photo by Dibyangshu Sarkar/AFP Photo)

An armed police officer attends an explosive ordnance disposal training on April 12, 2022 in Nanning, Guangxi Zhuang Autonomous Region of China. (Photo by Yu Haiyang/VCG via Getty Images)

A girl rides on a train as she takes part in the first edition of the No Pants Subway Ride in Bucharest, Romania, Sunday, January 11, 2015. The No Pants Subway Ride is an annual which was started in 2002 by Improv Everywhere in New York, the goal is for riders to get on the subway train dressed in normal winter clothes without pants and keep a straight face. (Photo by Vadim Ghirda/AP Photo)

In this picture taken on January 11, 2021, young gymnasts train at the Li Xiaoshuang Gymnastics School in Xiantao, Hubei province. This summer's delayed Tokyo Olympics, which are now due to start on July 23, 2021, will be the defining moment for Chinese gymnasts who have trained relentlessly since as young as age four in the pursuit of gold. (Photo by Nicolas Asfouri/AFP Photo)

A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)