In this September 27, 2017 file photo, girls walk past a wall riddled with bullet holes from shootings between rival drug traffickers, at the Rocinha slum, in Rio de Janeiro, Brazil. Violence is on the rise in Rio's slums after several years of decline, and the killings of kids have shocked even residents long inured to deaths from gangs and police. (Photo by Silvia Izquierdo/AP Photo)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

Svetlana Tseyko feeds a 10-month-old moose named Grisha in the courtyard in the village of Abramy, some 160 km northwest of Minsk, on February 21, 2017. (Photo by Sergei Gapon/AFP Photo)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Leslie Cliff and his wife Violet, English figure skating pair. Olympic games of Garmisch-Partenkirchen (Germany), 1936. (Photo by Roger Viollet Collection/Getty Images)

Model Heidi Klum in front of Concorde jet after arriving for Victoria's Secret fashion show at Cannes Film Festival on May 16, 2000. (Photo by Marion Curtis/DMI/The LIFE Picture Collection/Getty Images)

In this February 1, 2017 photo, environmental activist Maruja Inquilla poses for a photo next to a Municipal waste treatment plant with water that flows into Lake Titicaca, in Juliaca, in the Puno region of Peru. “If the frogs could talk they would say, This is killing me”," said Inquilla, who recently showed up at the Puno governor's house carrying plastic bags filled with hundreds of dead frogs in protest. (Photo by Rodrigo Abd/AP Photo)

Indian Students of Rabindra Bharati University at the BT Road Campuses Celebrates the Holi, Color Festival on March 09, 2017 in Kolkata.Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 13 this year. (Photo by Debajyoti Chakraborty/NurPhoto)