A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)

Children play football in front of an abandoned train compartment next to a railway track in Dhaka, in this May 29, 2014 file photo. (Photo by Andrew Biraj/Reuters)

People in Mexico wave at U.S. Border Patrol agents on horseback patrolling the U.S.-Mexico border fence near San Diego, California, U.S., November 10, 2016. (Photo by Mike Blake/Reuters)

The front wheels of a tractor, pulling a trailer overloaded with sugarcane, are seen lifted off the ground as it passes through the streets of Karor Lan Esan, Pakistan December 6, 2015. (Photo by Caren Firouz/Reuters)

A customer asks for the price of a bittergourd at Duri market on a railway track in Jakarta, January 8, 2016. Indonesia's annual inflation rate cooled to the lowest in six years in December, which might pave the way for the central bank to cut a benchmark rate held at 7.50 percent since February 2015. (Photo by Reuters/Beawiharta)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

A father crosses a road with his twin daughters in Shanghai, China September 28, 2018. (Photo by Aly Song/Reuters)