Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Young contortionists practice at a training school in Ulaanbaatar, Mongolia, July 4, 2016. (Photo by Natalie Thomas/Reuters)

This picture taken on October 20, 2016 shows students practising wushu at the Tagou martial arts school in Dengfeng. China is investing hugely in football training and has vowed to have 50 million school- age players by 2020, as the ruling Communist party eyes “football superpower” status by 2050. (Photo by Nicolas Asfouri/AFP Photo)

5-year-old Rina Kumari rubs her eye while cracking stones on the banks of Mahananda river in Siliguri, northeast India, March 5, 2005. Over 400 million people in India live below the internationally agreed poverty line (living on less than US $1 per day). According to estimates, several hundred thousand children work as labourers and beg on the streets in India. (Photo by Desmond Boylan/Reuters)

Members of a samba school warm up before parading along Copacabana Beach in Rio de Janeiro, Brazil, Saturday, January 6, 2018. Musicians and members from Rio de Janeiro's top 13 samba schools have paraded in an event aimed at promoting tourism ahead of Rio's world famous Carnival that begins early next month. (Photo by Leo Correa/AP Photo)

A little girl takes a picture of a lion in the zoo in Frankfurt, Germany, Tuesday, September 13, 2016. (Photo by Michael Probst/AP Photo)

A girl participates in a New Year calligraphy contest in Tokyo, Japan, January 5, 2017. (Photo by Kim Kyung-Hoon/Reuters)

A girl plays with coloured chicks for sale prior to Easter celebrations in Byblos, Lebanon on March 22, 2015. (Photo by Jamal Saidi/Reuters)