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)

Laborers work on scaffolding near a full-scale replica of the Sphinx at an unfinished movie and animation tourism theme park, in Chuzhou, Anhui province, March 27, 2015. (Photo by Reuters/China Daily)

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)

People pass a suitcase as they line up to enter a railway station in Beijing, February 15, 2015. Chinese Ministry of Transport said a total of 2.807 billion trips are expected to be made during the 40-day Spring Festival travel rush, which started on February 4 and will last until March 16, Xinhua News Agency reported. (Photo by Reuters/Stringer)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)

A performer gestures at the Harbin Ice-Snow World in Harbin, northeast China's Heilongjiang Province, December 25, 2021. The 23rd Harbin Ice-Snow World opened to the public on Saturday. (Photo by Xie Jianfei/Xinhua News Agency/Profimedia via AP Photo)