School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)

Wang Zeyu, 4, a fee-paying enthusiast of kung fu, practises during a training class at a kung fu school near the Shaolin Temple April 10, 2005 in Dengfeng, Henan Province, China. Zeyu's father sent him to the school from his home in Jiangsu Province, thousands kilometres away from Dengfeng, when he was just 3 years old. And his father must pay 9,800 yuan (US$1195) for one year's tuition at the school, a huge amount for most Chinese. There are more than 80 kung fu schools that line the road from the city of Dengfeng to the Shaolin Temple with hundreds and thousands of young kung-fu lovers from all over the country and beyond studying here. All the schools use the Shaolin name to attract students as the Shaolin Temple is the birthplace of Chinese Kung Fu. (Photo by Cancan Chu/Getty Images)

Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP Photo)

Heralds ride on horse-back through the streets of Moscow proclaiming the forthcoming coronation of Tsar Nicholas II, 1896. P.S. All pictures are presented in high resolution.

Afghan boys attend their Quran study sessions at the Islami Noor religious school on May 12, 2011 in Kandahar, Afghanistan. Despite recent multiple attacks near the city's downtown, children continue their studies at the school. (Photo by Majid Saeedi/Getty Images)

Revellers parade for Gavioes da Fiel samba school during carnival in Sao Paulo, Brazil, February 6, 2016. (Photo by Paulo Whitaker/Reuters)

Ulia Matos takes part in a school of theatre, makeup and hair styling graduation contest in Havana, November 16, 2015. (Photo by Reuters/Stringer)

Children ride on the back of a truck at a camp for internally displaced people (IDPs) in Marib, Yemen on September 9, 2021. (Photo by Ali Owidha/Reuters)