Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

A woman sits with a Great Dane during the first day of the Crufts dog show in Birmingham, central England March 6, 2014. (Photo by Darren Staples/Reuters)

A model prepares backstage at the Meskita fashion show during Mercedes-Benz Fashion Week Spring 2015 on September 4, 2014 in New York City. (Photo by Larry Busacca/Getty Images for Meskita)

U.S. Air Force pilots with the Thunderbirds perform the calypso pass maneuver in F-16 Fighting Falcon aircraft during a practice session prior to the Gunfighter Skies air show at Mountain Home Air Force Base, Idaho, September 19 and released September 24, 2014. (Photo by Tech. Sgt. Manuel J. Martinez/Reuters/US Air Force)

“Misty Morning”. Every morning, people expect sunny weather. Photo location: Bali, Indonesia. (Photo and caption by Henry Adam/National Geographic Photo Contest)

Ten segments of the Berlin Wall, which constitute the longest stretch outside of Berlin, are seen on display in Los Angeles, California September 18, 2014. On November 9, Germany will celebrate the 25th anniversary of the fall of the Berlin Wall. To mark the event Reuters Photographers around the world captured images of segments of the wall, which are kept as monuments in many countries from Taiwan to South Africa and Costa Rica. (Photo by Mario Anzuoni/Reuters)

A riot policeman uses a baton to hit a rioting University of Nairobi student in Kenya's capital Nairobi, in this May 20, 2014 file photo. (Photo by Noor Khamis/Reuters)

A woman receives a bouquet made of vegetables and flowers, priced at 238RMB, from a delivery staff of a florist outside an office building on Valentine's Day in Beijing, China, February 14, 2017. (Photo by Jason Lee/Reuters)