Boys pose with their toy guns as others play on swings, on the first day of the Muslim holiday of Eid al-Fitr, which marks the end of the holy month of Ramadan, in the government-controlled district of Dwelaa in Damascus, Syria July 6, 2016. (Photo by Omar Sanadiki/Reuters)

People clash with Venezuelan National Guards as they try to cross the border to Colombia over the Francisco de Paula Santander international bridge in Urena, Venezuela December 18, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)

A trader speaks on the phone at his desk at the Frankfurt stock exchange, Germany, in this June 29, 2015 file photo. Federal Reserve policymakers are widely seen raising interest rates for the first time in almost a decade at their next meeting this week. (Photo by Ralph Orlowski/Reuters)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

In this August 21, 2017 photo released by the U.S. Defense Department, Qatari special operations personnel conduct a military free-fall Friendship Jump over Qatar. The U.S. military has halted some exercises with its Gulf Arab allies over the ongoing diplomatic crisis targeting Qatar, trying to use its influence to end the monthslong dispute, authorities told The Associated Press on Friday, October 6, 2017. (Photo by Staff Sgt. Trevor T. McBride/ U.S. Air Force via AP Photo)

A horse buggy is headed for the stables on a foggy night in New Orleans, Monday, December 18, 2017. (Photo by David Grunfeld/NOLA.com The Times-Picayune via AP Photo)

Italy's Mount Etna, Europe's tallest and most active volcano, spews lava as it erupts on the southern island of Sicily, Italy, February 28, 2017. (Photo by Antonio Parrinello/Reuters)

The buildings of the banking district are seen through thousands of rain drops on a glass railing in central Frankfurt, Germany, Wednesday, January 11, 2017. (Photo by Michael Probst/AP Photo)