Yandex.Eda food delivery service employees by Barrikadnaya Station of the Moscow Metro in Moscow, Russia on April 12, 2020. Russian President Vladimir Putin has expanded non-working period till April 30, 2020 to prevent the spread of the novel coronavirus. (Photo by Sergei Savostyanov/TASS via Getty Images)

Overlooking qingshuitan Wetland Park in the air, thousands of Chinese fir trees turn green. Gaoyou City, Jiangsu Province, China, April 20, 2020. April 22 is world earth day. (Photo credit should read Costfoto/Barcroft Media via Getty Images)

Visitors take photos of the fluorescent sea in the waters of Paishi Village, Dalian City, Liaoning Province, China, May 24, 2020, from the night of May 24 to the early morning of May 25, 2020. The fluorescent sea in dalian is caused by noctilucent algae in the sea water. (Photo by Costfoto/Barcroft Media via Getty Images)

Visitors watch dinosaur models at Haitang Bay Rice Paddy Park on January 24, 2018 in Sanya, Hainan Province of China. The Haitang Bay Rice Paddy Park featuring 323 full-size dinosaur models was officially opened to the public on Thursday. (Photo by Yin Haiming/China News Service/VCG via Getty Images)

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)

A Chinese tourist visits the Mutianyu Great Wall covered in snow on February 23, 2021 in Beijing, China. Affected by the new coronavirus (COVID-19), the number of visitors to Mutianyu Great Wall in 2020 dropped by about 60%. (Photo by Lintao Zhang/Getty Images)

Actor Jackie Chan poses with student performers after participating in a leg of the Beijing 2022 Winter Olympics Torch Relay at the Badaling Great Wall on February 3, 2022 outside Beijing, China. (Photo by Kevin Frayer/Getty Images)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)