“The girl behind the camera and the girl in front of the camera”, May 2012. (Photo by: Mandy Rosen; Source: Flickr)

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

An oversized, prehistoric praying mantis wreaks havoc in a freeway underpass as it overturns cars and trucks, in a film still from “The Deadly Mantis”, directed by Nathan Juran, 1957. (Photo by Universal Pictures/Courtesy of Getty Images)

A woman wears a face mask in the part of the city near neighbourhoods known for burning coal for heating in Ulaanbaatar, Mongolia January 26, 2017. Not many people in Ulaanbaatar wear masks to protect themselves against pollution. (Photo by B. Rentsendorj/Reuters)

A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

People ride a bus as they travel in Yangon, Myanmar January 14, 2017. Picture taken January 14, 2017. (Photo by Soe Zeya Tun/Reuters)

This picture taken on March 1, 2016 shows a man running a mobile pig mating service and waiting outside a customer's home with his male pig in a cage pulled behind his motorcycle in the northern province of Bac Ninh. (Photo by Hoang Dinh Nam/AFP Photo)

A Hindu holy man or Sadhu walks back to his ashram after taking a dip at Sangam, confluence of Ganges river, Yamuna river and mythical Saraswati river in Allahabad, India, Thursday, August 4, 2016. (Photo by Rajesh Kumar Singh/AP Photo)