Workers clean empty cooking oil containers at a roadside recycling workshop in Kolkata, India, July 13, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)

A man carries an injured girl after what activists said were five air strikes by forces loyal to Syria's President Bashar al-Assad in Douma, eastern al-Ghouta, near Damascus September 11, 2014. (Photo by Bassam Khabieh/Reuters)

A girl paddles on her stand-up board on the waters of Guanabara bay at Bica beach in Rio de Janeiro Brazil, January 10, 2016. Few features capture the beauty, or the problems, of one of the world's most dramatic urban landscapes like Guanabara Bay - the finger-like inlet that forms the shoreline and harbor for Rio de Janeiro. The bay, which carves into southeast Brazil from the Atlantic Ocean, literally gave Rio its name when Portuguese mariners mistook it for a “rio”, or “river”. Four centuries later, the bay is preparing to welcome another sort of seafarer – Olympic sailors, who will navigate the bay when the 2016 Rio Olympics kick off in August. (Photo by Ricardo Moraes/Reuters)

A man poses for a photo with a life size cutout of Pope Francis at Bicentennial Park where the pontiff celebrated Mass for an estimated half-million people, in Quito, Ecuador, Tuesday, July 7, 2015. Francis told an estimated half-million people gathered for the Mass that in a world divide by wars, violence and individualism, Catholics should be “builders of unity”, bringing together hopes and ideals of their people. (Photo by Ana Buitron/AP Photo)

Jack London was a prolific photographer in addition to his writing. Here: Salvation Army barracks in London during Sunday morning rush – men who had been given tickets during the night queuing for free breakfast, 1902. (Photo by Jack London/Courtesy of Contrasto)

A girl walks in front of a graffiti painted on the wall of a house located inside the 15th-century complex built by Mameluk Sultan al-Ashraf Qaitbey, in Cairo's City of the Dead, Egypt February 13, 2017. (Photo by Amr Abdallah Dalsh/Reuters)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)