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)

Julya Baer, 30, attends a candlelight vigil and celebration of Prince's life in Leimert Park in memory of musician Prince on April 21, 2016, in Los Angeles, California. Prince died earlier today at his Paisley Park compound at the age of 57. (Photo by Kevork Djansezian/Getty Images)

A woman performs a dance during a demonstration for climate justice and against the war in Rome, Friday, March 25, 2022. Climate activists have staged a 10th series of worldwide protests to demand that leaders take stronger action against global warming. (Photo by Cecilia Fabiano/LaPresse via AP Photo)

Aleksandra Miroslaw, of Poland, competes during the speed portion of the women's sport climbing final at the 2020 Summer Olympics, Friday, August 6, 2021, in Tokyo, Japan. (Photo by Tsuyoshi Ueda/Pool Photo via AP Photo)

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 racegoer flashes her undies in front of the racing crowd during Caulfield Cup Day at Caulfield Racecourse on October 21, 2017 in Melbourne, Australia. (Photo by Splash News and Pictures)

Children riding on donkeys queue to fill their jerrycans with water from a cistern at a make-shift camp for the internally displaced in Yemen's northern Hajjah province on July 12, 2021, amidst an extreme heat wave and severe water shortage. (Photo by Essa Ahmed/AFP Photo)

Revellers attend the Play Time 2016 music festival on the outskirts of Ulaanbaatar, Mongolia, June 26, 2016. (Photo by Jason Lee/Reuters)