A cat sits on the empty Great Wall 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)

The mother of a protester mourns at a hospital after her son was killed was killed during clashes on March 03, 2021 in Yangon, Myanmar. Medics and health workers have found themselves on the front lines and under intense pressure, as they try to help anti-coup protesters as resistance continues to erupt across the country, to be met with deadly force by the military junta. (Photo by Stringer/Getty Images)

Kyuta Kumagai, 10, wrestles with a boy the same age as him, during a training session at Buddy acL Ariake's wrestling club in Tokyo, Japan, August 22, 2020. (Photo by Kim Kyung-Hoon/Reuters)

A member of a winter swimming club wears flippers during the celebration of Maslenitsa, also known as Pancake Week, a pagan holiday, marking the end of the winter, in Novosibirsk, Russia. (Photo by Alexandr Kryazhev/Sputnik/Profimedia)

Russian President Vladimir Putin, right, and North Korea's leader Kim Jong Un pose for photographers during their meeting in Vladivostok, Russia, Thursday, April 25, 2019. Putin and Kim are set to have one-on-one meeting at the Far Eastern State University on the Russky Island across a bridge from Vladivostok. The meeting will be followed by broader talks involving officials from both sides. (Photo by Alexander Zemlianichenko/AP Photo/Pool)

A lady wearing a mask feeds pigeons in St James' Park, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 5, 2020. (Photo by Henry Nicholls/Reuters)

In this March 30, 2020, photo, Zandile Mlotshwa, 21, cashier at Spar supermarket in the Norwood suburb of Johannesburg, counts her cash at the end of her shift. From South Africa to Italy to the U.S., grocery workers – many in low-wage jobs – are manning the front lines amid worldwide lockdowns, their work deemed essential to keep food and critical goods flowing. (Photo by Jerome Delay/AP Photo)

A security officer looks at a scanning screen for checking passengers' temperature at the Istanbul Airport in Istanbul, Turkey, on June 9, 2020. Technology and innovation will top the precautions of Turkey's biggest airport Istanbul Airport against the COVID-19 in the post-pandemic era, according to the management of the airport. The management on June 9 presented their final preparations and measures taken against coronavirus while Turkish airline companies are preparing to resume their international operations the next day. (Photo by Yasin Akgul/Xinhua News Agency via Getty Images)