American paratroopers from the the 82nd Expeditionary Rescue Squadron take part in training for rescue operations in East Africa in the last decade of April 2024. (Photo by Senior Airman Olivia Gibson/US Air Force/CMA)

Members of the Hitler Youth who are trained to report airstrikes repaining their bicycles. Published by: “Die Sirene”. 1942. (Photo by Herbert Hoffmann/Ullstein Bild via Getty Images)

A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

Freshmen take part in a military training at Chongqing City Vocational College on September 23, 2021 in Chongqing, China. (Photo by Chen Shichuan/VCG via Getty Images)

A Kenyan acrobatic member of the Mighty Jambo Circus Academy performs a stunt during their training routine at the academy in Nairobi, Kenya, 13 January 2021. (Photo by Daniel Irungu/EPA/EFE)

A lenticular cloud is seen during sunrise from Gokmen Aerospace Training Center (GUHEM) in Bursa, Turkiye on January 19, 2023. (Photo by Halit Mirahmetoglu/Anadolu Agency via Getty Images)

Two holidaymakers amuse themselves with a porter's trolley whilst waiting for their train at Euston Station, London, 5th August 1939. (Photo by A. J. O'Brien/Fox Photos/Getty Images)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)