Nature, singles winner: Frogs with their legs severed struggle to the surface, surrounded by frogspawn, after being thrown back into the water in Covasna, Romania. (Photo by Bence Mate/World Press Photo 2019)

A staff member demonstrates how she puts on the helmet of a mock space suit at the C-Space Project Mars simulation base in the Gobi Desert outside Jinchang, Gansu Province, China, April 17, 2019. The facility – comprising several interconnected modules including a greenhouse and a mock decompression chamber – opened its doors to the public. (Photo by Thomas Peter/Reuters)

Danielle Collins of the US reacts to a point in the first set while playing Caroline Wozniacki of Denmark during Round Two Women's Singles tennis match of the 2019 US Open at the USTA Billie Jean King National Tennis Center in New York on August 29, 2019. (Photo by Robert Deutsch/USA TODAY Sports)

A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)

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)

A man walks his dog as the sun sets in a park in Frankfurt, Germany, Monday, September 18, 2017. Cool damp weather is set to continue in this part of Germany for the next few days with temperatures in the mid teens Celsius. (Photo by Michael Probst/AP Photo)

A man who was set on fire by people accusing him of stealing during a rally against Venezuela's President Nicolas Maduro runs amidst opposition supporters in Caracas, Venezuela, May 20, 2017. (Photo by Marco Bello/Reuters)

Common squirrel monkeys observe their Christmas present, a box full of mealworms, at the South America enclosure of the Budapest Zoo, in Budapest, Hungary, 24 December 2017. (Photo by Photo by Attila Kovacs/EPA/EFE/Rex Features/Shutterstock)