Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

Militia members march in formation past Tiananmen Square during the military parade marking the 70th founding anniversary of People's Republic of China, on its National Day in Beijing, China on October 1, 2019. (Photo by Thomas Peter/Reuters)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

People view the sunrise scene at the Bund in Shanghai, east China, January 1, 2017. (Photo by Wang Hechun/Xinhua/Barcroft 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)

South African surfer Andy Marr rides a wave at Dungeons offshore reef in the Atlantic Ocean outside Cape Town, South Africa, 01 September 2016. The big wave surfing season is at its peak with winter swells driven by storms in the South Atlantic breaking on the Cape's outer reefs providing good conditions. Big wave surfers are competing in the 2016 Striped Horse Challenge and Rebel Sessions big wave competitons symultaneously throughout the season. (Photo by Nic Bothma/EPA)

Members of the Indian Border Security Force (BSF) demonstrate their skills on motor-bikes during the BSF Golden Jubilee Day celebration in New Delhi on December 1, 2015. (Photo by Money Sharma/AFP Photo)

A physically challenged girl looks at her brother as she is kept in a basin to seek alms from people on the street in Kano, Nigeria December 30, 2015. The girl has suffered from her condition since birth. (Photo by Reuters/Stringer)