Afghan protesters beat a policeman after a suicide attack that targeted crowds of minority Shiite Hazaras during a demonstration at the Deh Mazang Circle of Kabul on July 23, 2016. Islamic State jihadists claimed responsibility for twin explosions July 23 that ripped through crowds of Shiite Hazaras in Kabul, killing at least 61 people and wounding 207 others in apparently their deadliest attack in the Afghan capital. The bombings during a huge protest over a power transmission line could deepen sectarian divisions in a country well known for communal harmony despite decades of war. (Photo by Wakil Kohsar/AFP Photo)

A picture made available on 30 March 2016 shows members of the anti-terror squad of the local paramilitary force have a training in Suining, in southwest Sichuan province, China, 29 March 2016. (Photo by Zhong Min/EPA)

An American Marine readies to land on Guadalcanal during the five-month struggle for the island between late 1942 and early 1943. Three thousand miles south of Tokyo, Guadalcanal was a major shipping point for military supplies. The Allied victory there in February, 1943, marked a major turning point in the war after a string of Japanese victories in the Pacific. (Photo by Joe Scherschel/Time & Life Pictures)

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

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

An attendee dances at the start of the “Big Goth Dance Party” during the Porcupine Freedom Festival, or PorcFest, the Free State Project's annual summer gathering in Lancaster, NH on Wednesday, June 25, 2014. (Photo by Matthew Cavanaugh/The Washington Post)

Interior designer Zahra Afridi (R) kicks a punching bag during a kickboxing training session at her home in Islamabad February 10, 2014. Afridi runs her own interior design company. Her most recent project was a Classic Rock Coffee cafe in Islamabad. Though instability continues to plague Pakistan and many areas are dominated by social conservatism, some of the country's more affluent residents have worked to fashion a very different kind of lifestyle for themselves. Pictures of men and women taking part in all sorts of activities and professions – from being a pilates instructor, to a textile retail entrepreneur, to a member of a rock band – offer a different view of Pakistan to images of conflict that often make the news. (Photo by Zohra Bensemra/Reuters)

A woman wearing a face mask takes a photo on her phone in Covent Garden, London, Thursday, December 3, 2020. Britain became the first country in the world to authorize a rigorously tested COVID-19 vaccine Wednesday and could be dispensing shots within days – a historic step toward eventually ending the outbreak that has killed more than 1.4 million people around the globe. (Photo by Alberto Pezzali/AP Photo)