Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

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)

In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

Takeoka Chisaka, Hiroshima, Japan. “One morning in August 1945, I was walking home from the night shift at a factory in Hiroshima. As I reached my door, there was a huge explosion. When I came to, my head was bleeding and I had been blasted 30m away. The atomic bomb had detonated. When I found my mother, her eyes were badly burned. A doctor said they had to come out, but he didn’t have the proper tools so used a knife instead. It was hellish. I became a peace-worker after the war. In the 1960s, at a meeting at the UN, I met one of the people who created the atomic bomb. He apologised”. (Photo and caption by Sasha Maslov)

Members of the San Francisco Gay Freedom Day Marching Band and Twirling Corps do their thing down San Francisco's Market Street, June 27, 1982. Police estimate the crowd to be 300,000 for the Lesbian/Gay Freedom Day parade and rally. (Photo by Carl Viti/AP Photo)

Palestinian man Mohammed al-Hoor, 23, demonstrates his street workout skills in Nuseirat refugee camp, in the central Gaza Strip on May 2, 2017. (Photo by Mohammed Salem/Reuters)

British theoretical physicist Stephen Hawking, Cambridge University Professor and Fellow, circa 1985. Stephen Hawking, the brightest star in the firmament of science, whose insights shaped modern cosmology and inspired global audiences in the millions, has died aged 76. (Photo by Gemma Levine/Getty Images)

Masai women dressed in traditional clothes wear surgical masks as they wait for a ceremony marking World Elephant Day in the Amboseli National Park, Kenya, August 12, 2020. (Photo by Baz Ratner/Reuters)