A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)

A local wears a plastic water bottle with a cutout to cover her face, as she walks on a footbridge in Hong Kong on January 31, 2020, as a preventative measure following a virus outbreak which began in the Chinese city of Wuhan. The World Health Organization, which initially downplayed the severity of a disease that has now killed 170 nationwide, warned all governments to be “on alert” as it weighed whether to declare a global health emergency. (Photo by Anthony Wallace/AFP Photo)

A mother reacts as she pleads with police to allow her daughter to pass a checkpoint for cancer treatment after she arrived from Hubei province at the Jiujiang Yangtze River Bridge in Jiujiang, China, February 1, 2020. (Photo by Thomas Peter/Reuters)

A dog wearing face mask is seen on a street as the country is hit by an outbreak of the novel coronavirus, in Shanghai, China on March 2, 2020. (Photo by Aly Song/Reuters)

Chinese women wear protective masks as they are dressed in traditional clothing from the Qing Dynasty era outside a park on March 29, 2020 in Beijing, China. A limited section of the iconic tourist site was re-opened to the public this week allowing a smaller number of visitors to reserve tickets online in advance and to enter after passing health screening. (Photo by Kevin Frayer/Getty Images)

A train attendant wearing a protective face mask stands on a train to Wuhan, at the railway station in Beijing, China, 29 March 2020. Wuhan, the epicenter of the coronavirus outbreak, partly lifted the lockdown allowing people to enter the city after more than two months. Chinese authorities eased the quarantine measures as cases of Covid-19 across China have plummeted, according to Chinese government figures. (Photo by Roman Pilipey/EPA/EFE)

Visitors browse in the starry Art Museum. Shanghai, China, May 13, 2020. The exhibition hall uses a large number of mirror devices, combined with the layout of acousto-optic, to create a visual scene and spatial effect. (Photo by Costfoto/Barcroft Media via Getty Images)

Dressed in ancient Chinese clothes, children at a local kindergarten dance and make traditional perfumed medicine bag to celebrate the upcoming Dragon Boat Festival, Ganyu district, Lianyungang city, east China's Jiangsu province, 19 June 2020. (Photo by Imaginechina via AP Images)