Sudanese cattle keepers from Dinka tribe Makal Maker (R) and Achiek Butich pose with the guns for their protection at their cattle camp in Mingkaman, Lakes State, South Sudan, on March 2, 2018. (Photo by Stefanie Glinski/AFP Photo)

A rickshaw driver looks out the windshield as he drives onto the highway in Mardan, Pakistan January 30, 2017. (Photo by Fayaz Aziz/Reuters)

In this Monday, January 30, 2017 photo, wildfires straddle Chile's Dichato community. Strong winds are continuing to stoke the flames of raging wildfires in Chile, forcing the evacuation of more than 800 families in the coastal town of Dichato. (Photo by Esteban Felix/AP Photo)

As the world marks International Women's Day on Wednesday, whose theme this year focuses on “women in the changing world of work”, the Israeli military says it is ahead of the curve in providing combat roles for female soldiers. Here: A female Israeli soldier from the Haraam artillery battalion fixes her hair in the women's living quarters at a military base in the Israeli-occupied Golan Heights March 1, 2017. (Photo by Nir Elias/Reuters)

Joseph Szabo was a frustrated high-school teacher in need of inspiration – so he started photographing his students, and captured all the angst and excitement of being caught between childhood and adulthood. Here: “Priscilla”, 1969. (Photo by Joseph Szabo/Courtesy of Michael Hoppen Gallery/The Guardian)

Sunrise over Haleakala Crater, Haleakala National Park, Maui, Hawaii on April 26th, 2011. (Photo by Robert Bush/Alamy Stock Photo)

A hippopotamus is sprayed with water on a hot summer day at Anna National Zoological Park in Chennai, India on April 26, 2017. (Photo by Arun Sankar/AFP Photo)

A model wears a creation during the presentation of Chanel Cruise collection in Paris, Wednesday, May 3, 2017. Chanel is hosting its itinerant resort show, destined for glamorous women who sojourn on cruise ships. (Photo by Francois Mori/AP Photo)