A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

A migrant boy sits on railway tracks at a train station in Tovarnik, Croatia, September 20, 2015. (Photo by Antonio Bronic/Reuters)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A subway worker walks away after a train departed the station in central Pyongyang, North Korea May 7, 2016. (Photo by Damir Sagolj/Reuters)

An Iraqi army cadet participates in “the leap of faith”, from a bridge as part of their training, in Baghdad, Iraq on December 15, 2023. (Photo by Ahmed Saad/Reuters)

This handout picture released by the Gagarin Cosmonauts' Training Centre on October 17, 2023 shows Marina Vasilevskaya (L) flying during a parabolic flight aboard a zero-gravity simulator, a Russian IL-76 MDK aircraft used for cosmonauts' training flights in weightlessness, in Star City outside Moscow. (Photo by Pavel Shvets/Gagarin Cosmonaut Training Center/AFP Photo)

Mongolia's Olympic wrestler Battsetseg Soronzonbold (front) fights with her training partner during a daily training session at the Mongolia Women’s National Wrestling Team training centre in Bayanzurkh district of Ulaanbaatar, Mongolia, July 1, 2016. Battsetseg Soronzonbold became a national hero in her native Mongolia after winning wrestling bronze at the London Olympics and is determined to turn the medal into gold in Rio next month. (Photo by Jason Lee/Reuters)

Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)