Students attend a stewardess skill training for the upcoming 2017 entrance examination for art majors in colleges in Luoyang, central China's Henan Province, January 4, 2017. Along with how to stand, how to sit is also covered in these classes. (Photo by Li Bo/Xinhua/Barcroft Images)

These Arab recruits line up in a barracks square in the British Mandate of Palestine, on December 28, 1940, for their first drill under a British solider. Some 6,000 Palestinian Arabs signed up with the British Army during the course of World War II. (AP Photo)

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

Members of the Apollo Rainbow Dancers stretch out in special A train late on May 4, 1985, in New York. The legendary Apollo Theatre celebrated its 50th anniversary in an official reopening after a 15 month refurbishing with a celebrity studded evening. (Photo by Ray Stubblebine/AP Photo)

A protester reacts as riot police and army soldiers scuffle with anti-government protesters outside a military court, in Beirut, Lebanon, Monday, February 8, 2021. Riot police briefly clashed Monday in Beirut with hundreds of protesters demanding the release of anti-government activists detained following riots in northern Lebanon late last month. (Photo by Hassan Ammar/AP Photo)

Taras Mychalewych, 75, poses for a portrait with his vaccination card after receiving his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. (Photo by Paul Ratje/Reuters)

A man wearing a costume of the StarWars protagonist Din Djarin poses in front of a giant replica of the Razor Crest, a gunship from the StarWars spinoff series “The Mandalorian” used by the hit TV show's mysterious bounty hunter to roam the galaxy's outer reaches, in a park of the eastern Siberian city of Yakutsk on March 14, 2021. (Photo by Evgeniy Sofroneyev/AFP Photo)