Pupils of the Dao ethnic tribe return 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)

Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

In this file photo taken on Saturday May 1, 1993, an elderly communist woman clutches her head as police on horseback patrol the streets in Moscow. When Alexander Zemlianichenko started working as an AP photographer in Moscow, the Soviet Union was nearing its demise. (Photo by Alexander Zemlianichenko/AP Photo)

A man wearing a protective mask poses for a picture with a giant Jade Rabbit installation ahead of celebrations for the Mid-Autumn Festival, amid the coronavirus disease (COVID-19) outbreak in Kuala Lumpur, Malaysia on September 18, 2020. (Photo by Lim Huey Teng/Reuters)

Girls sits on a bench during summer at the Central Park in New York, United States, 2011. (Photo by An Rong Xu)

A police officer holds a pistol during clashes with protesters near a burning tyre barricade in the Kariobangi slum of Nairobi, Kenya Friday, May 8, 2020. Hundreds of protesters blocked one of the capital's major highways with burning tires to protest government demolitions of the homes of more than 7,000 people and the closure of a major food market, causing many to sleep out in the rain and cold because of restrictions on movement due to the coronavirus. (Photo by Brian Inganga/AP Photo)

Police detain a woman protesting against the court verdict for Yuliy Boyarshinov, and Viktor Filinkov, members of a left-wing group Set (Network) at the Western regional military court in St.Petersburg, Russia, Monday, June 22, 2020. A Russian military court convicted two members of a left-wing youth group of terrorism Monday and sentenced them to prison terms of five and a half and seven years, in a case that human rights groups called fabricated and based on coerced testimony. (Photo by Dmitri Lovetsky/AP Photo)