Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

A helicopter is silhouetted by glowing embers as it makes a water drop at the “Old Fire”, which burned in Calabasas, California, U.S., June 4, 2016. (Photo by Gene Blevins/Reuters)

A pilot steers his helicopter at night over Rio de Janeiro, Brazil, less than two weeks before the start of the Rio 2016 Olympic Games, July 23, 2016. Picture taken July 23, 2016. (Photo by Pawel Kopczynski/Reuters)

A staff member of Sony Computer Entertainment tries out PlayStation 4's virtual reality headset Project Morpheus at its booth in Tokyo Game Show 2014 in Makuhari, east of Tokyo September 18, 2014. (Photo by Yuya Shino/Reuters)

A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)

“Slow”. A calm cow in the messy streets of Jodhpur. Photo location: India. (Photo and caption by Matthias Troeger/National Geographic Photo Contest)

A man tries to photograph the interior of the driver's cab belonging to Eurostar's new Siemens e320 train at St Pancras station in central London, November 13, 2014. Eurostar, the company that runs passenger trains through the Channel tunnel between London and Paris, said it would buy seven additional e320 trains from Siemens for about 300 million pounds ($473 million). The company placed an order for 10 new trains in 2010, the first of which is due to enter commercial service next year, enabling the company to add new routes. (Photo by Andrew Winning/Reuters)

A nesting bird peeks out of the budding Japanese Yoshino cherry tree along the Tidal Basin in Washington, Sunday, April 7, 2013. Despite repeated predictions peak blossom time for the historic cherry trees is not yet here, but almost, almost. (Photo by Carolyn Kaster/AP Photo)