Young girls attend a training session in MGFSO Olympic reserve school in Moscow on May 30, 2016. (Photo by Kirill Kudryavtsev/AFP Photo)

A boy jumps into a pool of mud during the traditional “Bloco da Lama” or “Mud Street” carnival party, in Paraty, Brazil, Saturday, February 25, 2017. Legend has it the “bloco” was born in 1986 after local teens hiking in a nearby mangrove forest smeared themselves with mud to discourage mosquitoes and then wandered through Paraty. The party grew year after year, but revelers eventually were banned from parading in the colonial downtown after shopkeepers complained pristine white walls were stained with the hard-to-remove mud. (Photo by Mauro Pimentel/AP Photo)

A reveller parades on stage at the annual Trinidad and Tobago Red Cross Society's Children's Carnival Competition at the Queen's Park Savannah in Port-Of-Spain February 7, 2015. (Photo by Andrea De Silva/Reuters)

Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

North Korean children wave to people on a Chinese tourist boat on the banks of Yalu River near the Chongsong county of North Korea, opposite the Chinese border city of Dandong, May 8, 2011. (Photo by Jacky Chen/Reuters)

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)

A young girl sits on a mat, as worshippers arrive to pray to mark the Muslim Eid-al-Adha (Festival of Sacrifices) without observationg precautionary measures to curb the spread of COVID-19, in Kara, Ogun State in southwest Nigeria, on July 31, 2020. Nigerian Muslim faithfuls joined their counterparts across the world to celebrate Eid-El-Adha, Islamic festival of sacrifice. (Photo by Pius Utomi Ekpei/AFP Photo)

Ariana Lamcellari, 4, holds a sign at a protest against violence, following the charge of a British police officer in the London kidnapping and murder of Sarah Everard, in Dublin, Ireland on March 16, 2021. (Photo by Clodagh Kilcoyne/Reuters)