Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

A Chinese man uses an old film camera to take a picture of relatives near the Forbidden City on March 27, 2014 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

A youth in make-up waits for the start of the annual Zombie walk in Mexico City, Saturday, October 22, 2016. Hundreds dressed in rags and ghoulish makeup to look bloody and decaying, gathered in the historic center of Mexico's capital. (Photo by Christian Palma/AP Photo)

Canada's Marissa Papaconstantinou makes her way to the finish line after falling in the Women's 200m T44 Final during day ten of the IPC World ParaAthletics Championships 2017 at London Stadium on July 23, 2017 in London, England. (Photo by Peter Cziborra/Reuters)

This August 28, 2017 photo shows eight-year-old Indian girl Bharti performing a balancing act on a rope during a street show in Batala, India. Travelling Indian performers, who earn a meagre income from putting on shows on the streets, often scout areas to gather a large street audience who then give money on a collection plate at the end of the show. (Photo by Narinder Nanu/AFP Photo)

Japan's Kana Muramoto and Chris Reed compete in the figure skating team event ice dance short dance during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 11, 2018. (Photo by John Sibley/Reuters)

Anna Sloan and Vicki Adams of Britain sweep during a match against Olympic Athletes from Russia in Session 1 of the Women' s Round Robin curling competition at the 2018 Winter Olympic Games at Gangneung Curling Centre in Gangneung, South Korea on February 14, 2018. The British team won the match convincingly, 10-3. (Photo by Cathal McNaughton/Reuters)

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)