Syrian children listen to a teacher during a lesson in a temporary classroom in Suruc refugee camp on March 25 in Suruc, Turkey. The camp is the largest of its kind in Turkey with a population of about 35,000 Syrians who have fled the ongoing civil war in their country. Carl Court/Getty Images hide caption

Pope Francis talks with a delegation of the Leadership Conference of Women Religious during an audience in the pontiff's studio at the Vatican on Thursday. The Vatican announced the unexpected conclusion of a controversial overhaul of the main umbrella group of U.S. nuns. L'Osservatore Romano/AP hide caption

Tatiana Maslany (center) plays several different clones on the BBC America series Orphan Black. BBC America hide caption

Lauren Lattimore (left), Wi-Moto Nyoka, Edmund Alyn Jones and Courtney Harge rehearse a scene from Blue-Eyed Black Boy, a play about lynching that was written around 1930. Hansi Lo Wang/NPR hide caption

Joan Jett. Christopher Polk/Getty Images hide caption

High-definition video cameras with 30x magnification keep watch over the Boston Marathon finish line, where two bombs detonated in 2013, killing three people and injuring hundreds. Jesse Costa/WBUR hide caption

Phuong Nguyen, 55, and her son, Chris, who survived the bombing of the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995. StoryCorps hide caption

In the 1950s, the World Bank funded the creation of the world's largest man-made dam, the Kariba Dam, which sits on the border of Zimbabwe and Zambia. The construction of such dams can have dire consequences for poor people living near a river, an investigation found. Jekesai Njikizana/AFP/Getty Images hide caption