A military instructor helps a boy to shoot a rifle with blanks at a weapon exhibition during a military show in St.Petersburg, Russia, Sunday, January 17, 2016. (Photo by Dmitry Lovetsky/AP Photo)

A child coughs as migrants and refugees run away after Macedonian police fired tear gas at hundreds of Iraqi and Syrian migrants who tried to break through the Greek border fence in Idomeni, on February 29, 2016. Greek police said more than 6,000 people were massed at the border, in a buildup triggered by Austria and Balkan states capping the numbers of migrants entering their territory. (Photo by Louisa Gouliamaki/AFP Photo)

Dancer Chachi Gonzalez arrives at Nickelodeon's 2016 Kids' Choice Awards in Inglewood, California March 12, 2016. (Photo by Mario Anzuoni/Reuters)

Women pose for a picture at Havana city, Cuba, March 17, 2016. Obama arrives in Havana on Sunday for a historic visit that seals a rapprochement he and Cuban President Raul Castro agreed in December 2014 after 18 months of secret negotiations. (Photo by Ivan Alvarado/Reuters)

A woman poses for a photographer (not pictured) as a man sits next to her in downtown Catania, Italy April 20, 2016. (Photo by Tony Gentile/Reuters)

Rwandan refugees cross the Rusumo border to Tanzania from Rwanda carrying their belongings, goats, mattresses and cows, May 30, 1994. The bloodshed that claimed 800,000 Tutsi and moderate Hutu lives began 25 years ago on April 7, 1994, when a plane carrying Rwandan President Juvenal Habyarimana, Burundi President Cyprien Ntaryamira and a French air crew was shot down. (Photo by Jeremiah Kamau/Reuters)

Local residents evacuate onto a street minutes after an earthquake in central Kathmandu, Nepal, May 12, 2015. A 7.3 magnitude earthquake killed at least 37 people and spread panic in Nepal on Tuesday, bringing down buildings already weakened by a devastating tremor less than three weeks ago and unleashing landslides in Himalayan valleys near Mount Everest. The earthquake was centered 76 km (47 miles) east of the capital in a hilly area close to the border with Tibet, according to coordinates provided by the U.S. Geological Survey. (Photo by Athit Perawongmetha/Reuters)

Sandra, a 29-year-old orangutan at Buenos Aires' zoo, on May 20, 2015. Sandra got cleared to leave a Buenos Aires zoo that was her home for 20 years, after a court ruled she was entitled to more desirable living conditions. (Photo by Juan Mabromata/AFP Photo)