A man walks through the morning mist in a park in Rozzano, near Milan, northern Italy, Thursday, December 17, 2015. (Photo by Antonio Calanni/AP Photo)

Children hold signs thanking truck drivers hauling rocks to the Lake Oroville Dam after an evacuation was ordered for communities downstream from the dam in Oroville, California, U.S. February 13, 2017. (Photo by Jim Urquhart/Reuters)

A model presents a creation from Andres Sarda's Fall/Winter 2017 collection during the Mercedes-Benz Fashion Week in Madrid, Spain February 18, 2017. (Photo by Javier Barbancho/Reuters)

A reveller from Uniao da Ilha samba school performs during the second night of the carnival parade at the Sambadrome in Rio de Janeiro, Brazil February 27, 2017. (Photo by Pilar Olivares/Reuters)

Iraqi troops fire artillery towards Islamic State (IS) group jihadists' positions in west Mosul on March 11, 2017 during the ongoing battle to retake the city from the group. (Photo by Aris Messinis/AFP Photo)

Fireplace for children, Trondheim, Norway, by Haugen/Zohar. The children of Trondheim come to sit around the fire and tell stories in this whimsical cone hut, made with materials recycled from a construction site. (Photo by Jason Havneraas/The Guardian)

The space shuttle Atlantis lifts off from launch pad 39A at the Kennedy Space Center in Cape Canaveral, Florida May 14, 2010. (Photo by Pierre Ducharme/Reuters)

A cyclist drives past a flowering rapeseed field not far from the small Bavarian village of Schoengeising, near Munich, during a nice, warm sunny weather day on May 17, 2017. (Photo by Christof Stache/AFP Photo)