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)

A nurse at St. Joseph's Hospital wears a unique mask as the hospital celebrates the release of a COVID-19 patient after 45 days in their care during the outbreak of the coronavirus disease (COVID-19) in Orange, California, U.S., May 5, 2020. (Photo by Mike Blake/Reuters)

A street artist makes soap bubbles in front of the Alte Nikolaikirche church at the Roemerberg square in Frankfurt am Main, western Germany, on August 12, 2018. (Photo by Frank Rumpenhorst/DPA/AFP Photo)

A Palestinian horseman rides on the beach at sunset a few hours prior to the new year's celebrations, west of in Gaza city on December 31, 2018. (Photo by Mahmud Hams/AFP Photo)

People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)

Pakistani vendors carry animals in a bus for the upcoming Muslim festival Eid al-Adha in Lahore, Pakistan, Monday, August 5, 2019. Eid al-Adha, or Feast of Sacrifice, is the most important Islamic holiday and marks the willingness of the Prophet Ibrahim (Abraham to Christians and Jews) to sacrifice his son. (Photo by K.M. Chaudhry/AP Photo)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)

Demonstrators clash with riot police during a protest against President Sebastian Piñera on October 21, 2019 in Santiago, Chile. President Sebastian Piñera suspended the 3.5% subway fare hike and declared the state of emergency for the first time since the return of democracy in 1990. Protests had begun on Friday and developed into looting and arson, generating chaos in Santiago, Valparaiso and a dozen other cities resulting in at least 8 dead. (Photo by Marcelo Hernandez/Getty Images)