Two women react to the camera as Nightclub Circus hosts the first dance event, which will welcome 6,000 clubbers to the city's Bramley-Moore Dock warehouse on April 30, 2021 in Liverpool, England. The event is part of the national Events Research Programme which will provide data on how events could be permitted to safely reopen. (Photo by Anthony Devlin/Getty Images)

A security officer looks at a scanning screen for checking passengers' temperature at the Istanbul Airport in Istanbul, Turkey, on June 9, 2020. Technology and innovation will top the precautions of Turkey's biggest airport Istanbul Airport against the COVID-19 in the post-pandemic era, according to the management of the airport. The management on June 9 presented their final preparations and measures taken against coronavirus while Turkish airline companies are preparing to resume their international operations the next day. (Photo by Yasin Akgul/Xinhua News Agency via Getty Images)

A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

A Tibetan woman displays her Qing Dynasty family dress in Zhailong Village on April 24, 2005 in Danba County of Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China. (Photo by China Photos/Getty Images)

An Anti-Capitalist protestor from the Occupy LSX movement at St. Paul's Cathedral on February 22, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)

“As a photographer, peregrinator and naturalist, I have been searching for the ultimate unworldly world. I've always been drawn to unusual travel destinations. For me, to lose myself in a different culture is a great way to find balance in my life...”. – Li Xinzhao. (Photo by Li Xinzhao)

Bao Bao, the Giant Panda cub is seen by the media for the first time January 6, 2014 inside his glass enclosure at the Smithsonian's National Zoo in Washington, DC, a few days before going on display to the general public. Bao Bao was born at the Smithsonian's National Zoo August 2, 2013. (Photo by Paul J. Richards/AFP Photo)

Chinese archaeologists announced the discovery of 110 life-sized terracotta warriors, guarding the tomb of Qin Shi Huang, China's first emperor.

Photo: Archaeologists work on a terracotta warrior in the third excavation of pit one at the Terracotta Warriors and Horses Museum in Xi'an in northwest China's Shaanxi province Saturday, June 9, 2012. (Photo by AP)