The sun rises through the thick fog that covers the city of Frankfurt, Germany, Friday, November 12, 2021. (Photo by Michael Probst/AP Photo)

In this picture taken on January 11, 2021, young gymnasts train at the Li Xiaoshuang Gymnastics School in Xiantao, Hubei province. This summer's delayed Tokyo Olympics, which are now due to start on July 23, 2021, will be the defining moment for Chinese gymnasts who have trained relentlessly since as young as age four in the pursuit of gold. (Photo by Nicolas Asfouri/AFP Photo)

Greece's Maria Sakkari reacts during her women's singles quarter-final tennis match against Poland's Iga Swiatekon Day 11 of The Roland Garros 2021 French Open tennis tournament in Paris on June 9, 2021. (Photo by Gonzalo Fuentes/Reuters)

A lion rests in the Nairobi National Park, Kenya on January 6, 2021. (Photo by Tiksa Negeri/Reuters)

Palestinian children practise parkour along a beach in Gaza City at sunset on January 27, 2021. (Photo by Mohammed Abed/AFP Photo)

A tree covered with hoarfrost casts a shadow on a snowy field, shot with a drone in Sieversdorf-Hohenofen, Germany on January 31, 2021. (Photo by Patrick Pleul/dpa)

A stunt rider performs on the wooden wall during a fair in Bogra, Bangladesh, February 10, 2021. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

The sunrise at Boscombe beach at Bournemouth in Dorset, southwest United Kingdom on February 23, 2021. (Photo by Steve Hogan/pictureexclusive.com)