A Chesterfield Borough Police telephone operator tests a gasmask with built in earpiece and microphone. The telephone service is considered one of the most important links in the coordination of ARP operations and must remain operational during air raids, 12th April 1939. (Photo by Fox Photos/Hulton Archive/Getty Images)

This photo taken on February 9, 2020 shows children playing in front of their homes in Tarmaw Lawri village in the Lahe township in Myanmar's Sagaing region. A haunting refrain pierces the night as the tribeswomen of the Gongwang Bonyo, among the most isolated people in Myanmar, dance around a campfire to bless the harvest ahead. (Photo by Ye Aung Thu/AFP Photo)

Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)

Camila Hormazabal, a 24-year-old sеx worker, uses a laptop to connect to the web and keep an online erotic meeting with a virtual customer in Concepcion, Chile on April 7, 2020. Hormazabal reinvented herself offering sexual services online after the nightclub where she had worked was closed due to the outbreak of the coronavirus disease (COVID-19). (Photo by Juan Gonzalez/Reuters)

A man flies a kite made of 110 Tukkal or paper lanterns for the Hindu festival of “Makar Sankranti”, which marks the start of spring, in Ahmedabad January 13, 2011. (Photo by Amit Dave/Reuters)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)