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)

Students run out of their school celebrating their high school graduation at Nacka Gymnasium following the spread of the corona virus disease (COVID-19) in Stockholm, Sweden, June 3, 2020. (Photo by Jessica Gow/TT News Agency via Reuters)

Siberian tigers are fed by visitors from a bus at the Siberian Tiger Park in Harbin, in China's northeastern Heilongjiang province, on January 6, 2023. (Photo by Hector Retamal/AFP Photo)

Fluffy toy panda bears as part of the art installation “Panda mie” by Italian restaurant owner Giuseppe “Pino” Fichera sit over beers at his restaurant “Pino's” to raise awareness of the COVID-19 lockdown's business impact on gastronomy in Frankfurt, Germany, November 24, 2020. (Photo by Kai Pfaffenbach/Reuters)

Shoppers walk down stairs featuring a five-metre-high reproduction of Vincent van Gogh's signature painting “Sunflowers”, at the entrance to Ocean Terminal in Hong Kong July 15, 2013. A premium three-dimensional reproduction of works of Van Gogh, the RELIEVO collection, approved by the curators of the Van Gogh Museum in Amsterdam, is on display at a gallery inside Harbour City shopping mall attached to the terminal. (Photo by Bobby Yip/Reuters)

A dog wearing face mask is seen on a street as the country is hit by an outbreak of the novel coronavirus, in Shanghai, China on March 2, 2020. (Photo by Aly Song/Reuters)

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)