Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

The Tianzi Hotel with the shape of Chinese deities Fu, Lu and Shou is pictured on November 20, 2017 in Langfang, Hebei Province of China. The 41.6-meter-tall Tianzi Hotel has an exterior of Chinese Sanxing, whose names are Fu, Lu and Shou with the qualities of prosperity, status and longevity in traditional Chinese culture, in Langfang city. (Photo by VCG/VCG via Getty Images)

A Sadhu or a Hindu holy man performs to receive money from pilgrims at a makeshift shelter, before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India, January 10, 2018. (Photo by Rupak De Chowdhuri/Reuters)

Spacewalker Mark Vande Hei took his own photograph during the first spacewalk of 2018, on January 23, 2018. These sky-high pictures are better known as “space-selfies”. (Photo by Mark Vande Hei/NASA)

The homemade Airbus A320 jet plane made by Chinese farmer Zhu Yue is being built at an open space in Kaiyuan city, northeast China's Liaoning province on February 4, 2018. (Photo by Imaginechina/Rex Features/Shutterstock)

Leslie Cliff and his wife Violet, English figure skating pair. Olympic games of Garmisch-Partenkirchen (Germany), 1936. (Photo by Roger Viollet Collection/Getty Images)

A young woman looks at her smartphone sitting in front of a mannequin use to keep social distancing at a Chinese cuisine restaurant in Tokyo, Japan, 27 July 2020. Japan's total number of COVID-19 cases crossed the 30,000 line showing the new coronavirus pandemic is spreading across the country and not only in Tokyo and Osaka megalopolis. (Photo by Franck Robichon/EPA/EFE)