Prince Philip, Duke of Edinburgh practicing his bicycle polo technique, Windsor Great Park, Berkshire, 1964. (Photo by Norman Potter/Daily Express/Hulton Archive/Getty Images)

In this photo taken on Saturday, March 9, 2019, a visitor dances in front of a sculpture burning at the Maslenitsa (Shrovetide) festival at the Nikola-Lenivets art park in Nikola-Lenivets village, about 200 kilometers (125 miles) south-west of Moscow, Russia. As part of the celebrations of Maslenitsa (Shrovetide) Holiday in Russian, a folk holiday which heralds the beginning of spring, contemporary artist and park founder Nikolay Polissky built a giant sculpture made of wood and hay which was burnt to ashes during a traditional bonfire. (Photo by Alexander Zemlianichenko Jr./AP Photo)

Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

Girls practice sit-ups during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, on May 4, 2016. China's sports system has been enormously successful since the country returned to the Olympic fold in 1980, culminating with the host nation topping the medals' table at the 2008 Beijing Olympics. And yet, with the Rio de Janeiro Games less than three months away, the system is beginning to break down due to the shifting demographics of a more prosperous nation. (Photo by Aly Song/Reuters)

A dancer attends the final rehearsal for the new “VIVID Grand Show” at Friedrichstadt-Palast in Berlin, Germany, September 26, 2018. (Photo by Hannibal Hanschke/Reuters)

An Atlantic seal pup lies amongst the rocks at St Martin's Haven, Pembrokeshire, Wales, Britain October 8, 2018. Seal pups are born with fluffy white non-waterproof coats which they moult out in their fourth week. (Photo by Rebecca Naden/Reuters)

A youth skates next to a road in Palembang, South Sumatra, Indonesia on August 15, 2018. (Photo by Edgar Su/Reuters)

Iraqi boys swim with a herd of buffaloes in the Diyala River in the Faziliah district, east of Baghdad on August 2, 2021, amid extreme summer temperatures. As Iraq bakes under a blistering summer heat wave, its hard-scrabble farmers and herders are battling severe water shortages that are killing their animals, fields and way of life. (Photo by Ahmad Al-Rubaye/AFP Photo)