A Boeing 777-300 from Swiss International Airlines lands on a foggy morning at Zurich Airport, on Friday, October 13, 2017, in Zurich, Switzerland. The high humidity renders the air vortex visible. (Photo by Christian Merz/Keystone via AP Photo)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

A man dressed as Santa Claus skateboards down Fifth Avenue towing a dog before the annual Christmas tree lighting ceremony at Rockefeller Center in New York on December 5, 2019. (Photo by John Angelillo/UPI/Barcroft Media)

Iraqi children play with a ball on a street blocked with burning tyres, amid a general strike in the southern city of Basra, on November 25, 2019. The demonstrations rocking the capital and Shiite-majority south since October 1 are the biggest grassroots movement the country has seen in decades. Sparked by outrage over rampant government corruption, poor services and lack of jobs, they have since gone straight to the source: calling out the ruling system as inherently flawed and in need of a total overhaul. (Photo by Hussein Faleh/AFP Photo)

A woman walks past murals adorning the walls of Garibaldi subway station, in Milan, Friday, February 28, 2020. Due to the COVID-19 virus outbreak in northern Italy, the bustling metropolis of Milan has resembled more of a ghost town lately, as workers stayed home and tourism has dwindled there, and other parts of Italy. (Photo by Luca Bruno/AP Photo)

A citizen wearing protective suit shops at a market in Santiago, Chile, April 16, 2020 Chile has taken stringent measures to contain the virus, including imposing a night time curfew, suspending classes, closing non-essential businesses, and mandating the use of face masks on all public transit. (Photo by Jorge Villegas/Xinhua News Agency)

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)