Freshmen in Zhengzhou Institute of Aeronautical Industry Management head bottles of mineral water for upright stand during military training on September 17, 2015 in Zhengzhou, Henan Province of China. More than 6,800 freshmen in the school are required to take part in the military training. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

A dog from the K9 Division of the Sri Lanka Army’s Commando Regiment performs during an event to mark International Children’s Day at a school in Welisara, Colombo, Sri Lanka, 01 October 2016. Sri Lanka marks the Children's Day on 01 October with more emphasis on prevention of child abuse. (Photo by M.A. Pushpa Kumara/EPA)

A Thai mahout and his elephant, both dressed as Santa Claus pass in font of a large photograph of Thai King Bhumibol Adulyadej following a Christmas event at a school in the world heritage city of Ayutthaya, north of Bangkok, Thailand, 24 December 2015. The annual event is held to celebrate the Christmas season in the overwhelmingly Buddhist kingdom. (Photo by Diego Azubel/EPA)

A girl eats a watermelon slice while at a school building where Syrians – displaced from the area of Ras al-Ain by the Turkish offensive on the northeast – are staying in the city of Hasakah, on June 30, 2020. (Photo by Delil Souleiman/AFP Photo)

In this picture taken on January 11, 2021, young gymnasts train at the Li Xiaoshuang Gymnastics School in Xiantao, Hubei province. This summer's delayed Tokyo Olympics, which are now due to start on July 23, 2021, will be the defining moment for Chinese gymnasts who have trained relentlessly since as young as age four in the pursuit of gold. (Photo by Nicolas Asfouri/AFP Photo)

Girls ride an improvised motorbike public transport along with bicycles they received from their school under a government scheme in Malancha, South 24 Pargana district, India, Wednesday, October 20, 2021. (Photo by Bikas Das/AP Photo)