National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

A model wears a face mask to help prevent the spread of the coronavirus, designed by Iraqi designer Ziad Tariq at his workshop in Basra, Iraq, Monday, July 20, 2020. (Photo by Nabil al-Jurani/AP Photo)

Lindsey Vonn of USA wins the bronze medal during the FIS World Ski Championships Women's Downhill on February 10, 2019 in Are Sweden. (Photo by Leonhard Foeger/Reuters)

Danielle Collins of the US reacts to a point in the first set while playing Caroline Wozniacki of Denmark during Round Two Women's Singles tennis match of the 2019 US Open at the USTA Billie Jean King National Tennis Center in New York on August 29, 2019. (Photo by Robert Deutsch/USA TODAY Sports)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

A tourist pauses for photos with her mask on at Sensoji Temple Thursday, January 30, 2020, in Tokyo. The country began evacuating Japanese citizens on Wednesday from the Chinese city Wuhan hardest-hit by the virus. (Photo by Jae C. Hong/AP Photo)

An air plane takes off from the airport as air traffic is effected by the spread of the coronavirus disease (COVID-19) in Frankfurt, Germany, March 16, 2020. (Photo by Kai Pfaffenbach/Reuters)

Confiscated rare and protected wildlife products such as these stuffed Sumatran tiger skins are burned and destroyed during a ceremony by government forestry and wildlife officials in Banda Aceh, Aceh province, Indonesia May 23, 2016 in this photo taken by Antara Foto. (Photo by Irwansyah Putra/Reuters/Antara Foto)