A hippopotamus is sprayed with water on a hot summer day at Anna National Zoological Park in Chennai, India on April 26, 2017. (Photo by Arun Sankar/AFP Photo)

A pupil of the Dao ethnic tribe returns 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)

This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)

An Afghan woman clad in burqa begs in a snow-covered street in Kabul, Afghanistan on January 7, 2020. (Photo by Mohammad Ismail/Reuters)

Tourists sit around a bonfire on the Makgadikgadi salt pan in Botswana. (Photo by Yang Mengxi/Xinhua News Agency/Barcroft Media)

A man and a woman take a selfie on Russian Navy Day in St Petersburg, Russia on July 26, 2020. (Photo by Roman Pimenov/TASS)

A tufted puffin is seen in Kamchatka Territory, Russia on July 17, 2018. (Photo by Yuri Smityuk/TASS)

A swarm of starlings flies over the Altare della Patria monument (Unknown soldier) in the city centre of Rome during sunset, on November 27, 2018. (Photo by Vincenzo Pinto/AFP Photo)