A policeman reacts during a clash with protestors during a protest against the proposed changes to France's working week and layoff practices, in Lyon, central France, Thursday, April 28, 2016. French protesters are back on the streets over proposed reforms to the country's labor rules and strikers have forced cancellations and delays at two airports serving Paris. (Photo by Laurent Cipriani/AP Photo)

An environmental activist adjusts his mask while taking part in “The Dead Sea Swim Challenge”, swimming from the Jordanian to Israeli shore, to draw attention to the ecological threats facing the Dead Sea, in Kibbutz Ein Gedi, Israel November 15, 2016. Swimmers from around the world plunged into the salty waters of the Dead Sea on Tuesday to attempt a seven-hour swim across the fabled lake in a bid to draw attention to its environmental degradation. Wearing protective masks and snorkels, 25 swimmers paddled through the muddy water to attempt the 9-mile (15-kilometer) swim from Jordan to Israel. (Photo by Nir Elias/Reuters)

View of Evolutions installation by artist Yann Nguema at the Saint-Jean Cathedral during the rehearsal for the Festival of Lights (Fetes des Lumieres) in Central Lyon, France, late December 7, 2016. (Photo by Emmanuel Foudrot/Reuters)

A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)

In this photo taken Wednesday, March 8, 2017, a hospitality staff member pose for photos near the shadow of a tall light pole near the Great Hall of the People where a plenary session of the National People's Congress is held in Beijing, China. (Photo by Ng Han Guan/AP Photo)

A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

Kaylee Cantler, 15, of Waynesboro, Pa., applies blush during a natural makeup exercise at a modeling camp at the Courtyard Marriott Hotel in McLean, Va., on Monday, August 17th, 2015. (Photo by Brittany Greeson/The Washington Post)

A hyena eyes a herd of zebra at Lake Nakuru National Park, Kenya, August 19, 2015. The Park is home to some of the world's most majestic wildlife including lions, rhinos, zebras and flamingos. The scenery is stunning, from forests of acacia trees to animals congregating at the shores to drink. UNESCO says that with rapid population growth nearby, the area is under "considerable threat from surrounding pressures," particularly deforestation, a contributing factor in floods. (Photo by Joe Penney/Reuters)