A man shaves blocks of salt from the Danakil Depression on 28 March 2017, in Afar, Ethiopia. Every morning, hundreds of men converge on a dry lakebed in a remote corner of Ethiopia, where they cleave the ground open with handaxes to extract salt, just as their fathers and grandfathers once did. (Photo by Zacharias Abubeker/AFP Photo)

In this Sunday, March 11, 2017 photo, children fight in a boxing ring in Chitungwiza, Zimbabwe. Zimbabwean boys as young as 10 hurry every weekend to a boxing ring whose nickname, Wafa Wafa, in the local Shona language suggests that whoever enters will be lucky to come out alive. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Competitors pose backstage during the Arnold Classic South America bodybuilding event in Sao Paulo, Brazil, April 22, 2017. (Photo by Nacho Doce/Reuters)

Amanda Lepore attends the “Doll Parts” book launch party at The Standard, Highline on April 18, 2017 in New York City. (Photo by J. Kempin/Getty Images)

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)

This combination of pictures created on April 30, 2017 competitors posing before a beard and moustache competition at the Ecomusee d'Alsace in Ungersheim on April 30, 2017. (Photo by Sebastien Bozon/AFP Photo)

Participants arrive at the finish line during the annual Maldon Mud Race in Maldon, east England on May 7, 2017. Originating in 1973, the race involves competitors racing around a course through the River Blackwater in Essex at low tide. (Photo by Daniel Leal-Olivas/AFP Photo)

Actress and model Charlotte McKinney attends the grand opening of NightSwim at Encore Beach Club at Wynn Las Vegas on May 5, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Wynn Las Vegas)