A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

Tibetan monks dressed as demons attend the Beating Ghost festival at the Yonghe Temple, also known as the Lama Temple, in Beijing on March 19, 2015. The Beating Ghost festival, or Da Gui festival in Chinese, is an important ritual of Tibetan Buddhism and is believed to expel evil spirits and shake off troubles. (Photo by Wang Zhao/AFP Photo)

Players battle for the ball during their match at the swamp soccer China tournament in Beijing, June 26, 2014. The 32 teams from across the country participated in the soccer event to celebrate the 2014 World Cup in Brazil. (Photo by Kim Kyung-Hoon/Reuters)

Chinese women holding toy guns dance for a revolutionary song during their daily exercise at a square outside a shopping mall in Beijing, June 29, 2014. About 30 local residents formed this “Nanguan” art group that enjoys performing to revolutionary songs and dance performances as part of their daily fitness activities at night. (Photo by Jason Lee/Reuters)

Models wait backstage ahead of their presentation of creations from the YINMU collection by designer Wei Jiang during the China Fashion Week in Beijing, China, 26 October 2020. The fashion event runs from 24 October to 01 November 2020. (Photo by Wu Hong/EPA/EFE)

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)