Shan boys pray before they have their heads shaved in anticipation of their ordination in the Poy Song Long Ceremony at Wat Pa Pao in Chiang Mai, Thailand on April 3, 2018. Poy Sang Long (“The Festival of the Crystal Sons”) is a ceremony that marks a rite of passage among the Buddhist Shan people in Myanmar and northern Thailand. Boys between seven and fourteen years of age are ordained as Buddhist novices during a three day ceremony. Before the ceremony starts the boys have their heads shaved. (Photo by Jack Kurtz/ZUMA Wire/Rex Features/Shutterstock)

Models get ready backstage before the presentation of the Etam Live Show Lingerie at the Fashion Week in Paris, France, September 27, 2016. (Photo by Charles Platiau/Reuters)

Runners sleep before competing in the 2016 New York City Marathon in the Manhattan borough of New York City, NY, U.S. November 6, 2016. (Photo by Eduardo Munoz/Reuters)

A combination picture shows Aleppo's Umayyad mosque, Syria, before it was damaged on March 12, 2009 (top) and after it was damaged (bottom) December 13, 2016. (Photo by Omar Sanadiki/Reuters)

Beauty contestants prepare backstage before the fashion show of Miss Tiffany's Universe 2016 transvestite contest in Bangkok, Thailand, April 20, 2016. (Photo by Athit Perawongmetha/Reuters)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

English fashion designer Mary Quant (R) with a group of models at Heathrow Airport, before leaving for a continental fashion tour, 18th March 1968. (Photo by Express/Getty Images)

Models get prepared backstage before Wagner Kallieno Winter Collection 2016 show during Sao Paulo Fashion Week in Sao Paulo, Brazil, October 23, 2015. (Photo by Paulo Whitaker/Reuters)