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)

This is a portion of the first color 360-degree panorama from NASA's Curiosity rover, made up of thumbnails, which are small copies of higher-resolution images. The mission's destination, a mountain at the center of Gale Crater called Mount Sharp, can be seen in the distance, to the left, beginning to rise up. The mountain's summit will be imaged later. (Photo by NASA/JPL-Caltech/MSSS)

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge kiss on the balcony at Buckingham Palace on April 29, 2011 in London, England. The marriage of the second in line to the British throne was led by the Archbishop of Canterbury and was attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Peter Macdiarmid/Getty Images)

In this Wednesday, January 27, 2016 photo, Jung Myoung Sook, 61, holds her puppies she rescued at a shelter in Asan, South Korea. In the country, where dogs are considered a traditional delicacy and have only recently become popular as pets, Jung's love for her canine friends is viewed by some as odd. But others see her as a champion of animal rights. (Photo by Lee Jin-man/AP Photo)

A construction worker sweeps up as the final touches are completed on “Comedy Carpet” by British artist Gordon Young, the latest art installation on Blackpool's promenade on October 7, 2011 in Blackpool, England. (Photo by Christopher Furlong/Getty Images)

First class seat of Emirates Airbus A380 registration A6-EDP at Munich Airport Franz Joseph Strauss on November 25, 2011 in Munich, Germany. Emirates Airlines has launched a new daily A380 service from Dubai to Munich with its first flight. (Photo by Alexander Hassenstein/Getty Images)

The Mount Bromo volcano erupts in the Bryce Canyon, Utah. (Photo by Reynold Dewantara/2016 National Geographic Travel Photographer of the Year Contest)