A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925

Macaque monkeys crowd together in their cage at a monkey farm on February 3, 2016 in Xinye county, Henan province, China. The area boasts a centuries-long and lucrative history of raising and training monkeys for performance. In Xinye, villagers are seeing an increase in business with the lunar calendar's “Year of the Monkey”. Farmers say most of the monkeys are bred and raised for domestic zoos, circuses, and performing groups, but add that some are also sold for medical research in China and the United States. Despite the popularity of the tradition, critics contend the training methods and conditions constitute animal cruelty. (Photo by Kevin Frayer/Getty Images)

A woman carrying a child on her back looks at wigs on sale at the Baragwanath Taxi Rank in Soweto, South Africa, Wednesday, September 16, 2020. South African president Cyril Ramaphosa is scheduled to address the nation later in the day, as case numbers and death from COVID-19 hit the lowest in months. (Photo by Jerome Delay/AP Photo)

A view of a large poster depicting Russian opposition leader Alexei Navalny behind bars with a dove freeing him from detention, by an unidentified street artist known as Harry Greb, in downtown Rome, Italy, 25 January 2021. Navalny was detained after his arrival to Moscow from Germany on 17 January 2021. A Moscow judge on 18 January ruled that he will remain in custody for 30 days following his airport arrest. Navalny urged Russians to take to the streets to protest against President Putin's rule. (Photo by Fabio Frustaci/EPA/EFE)

A Chinese woman wears traditional dress, or hanfu, as she has her picture taken by friends next to the first blossoms of spring at a park on March 21, 2021 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

An aerial view shows local residents visiting a river side park in Taipei during the Lunar Mew Year on February 19, 2021. (Photo by Sam Yeh/AFP Photo)

People wearing protective face masks amid the coronavirus disease (COVID-19) outbreak are seen near foodstuffs, which are displayed for sale on a car in Omsk, Russia on December 4, 2020. (Photo by Alexey Malgavko/Reuters)