A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)

Visitors crowd an artificial wave swimming pool at a tourist resort to escape the summer heat in Daying county of Suining, Sichuan province, China, July 11, 2015. (Photo by Reuters/Stringer)

A beluga whale sprays water towards visitors during a summer attraction at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on July 20, 2015. Tokyo's temperature climbed over 34 degree Celsius on July 20, one day after the end of the rainy season. (Photo by Toshifumi Kitamura/AFP Photo)

Russia's synchronised swimming duet Aleksandr Maltsev (L) and Darina Valitova compete in the Mixed Duet Technical preliminary during the synchronised swimming competition at the 2015 FINA World Championships in Kazan on July 25, 2015. (Photo by Christophe Simon/AFP Photo)

A woman walks past a giant Pac-Man in Tokyo's Shinjuku area, Wednesday, August 12, 2015. The three-meter (about nine feet and 10 inches)-tall Pac-Man and other video game characters, made of Lego bricks, were on display to promote the upcoming movie “Pixels”. (Photo by Ken Aragaki/AP Photo)

2000 attended a welcome party at TigerTiger Manchester which was the first event in set of big club night for new students to Manchester and Salford universities in Manchester, UK on September 19, 2016. This year, university bosses have stepped up security in Manchester. (Photo by Jordan Sinclair/UK News Pictures)

A woman made up as a skull participates in Day of the Dead festivities in Mexico City, Thursday, October 27, 2016. The holiday honors the dead as friends and families gather in cemeteries to decorate their loved ones' graves and hold vigil through the night on Nov. 1 and 2. (Photo by Marco Ugarte/AP Photo)

Men are held by Iraqi national security agents, to be interrogated at a checkpoint, as oil fields burn in Qayara, south of Mosul, Iraq, Saturday, November 5, 2016. Islamic State fighters launch counterattacks in the thin strip of territory Iraqi special forces have recaptured in eastern Mosul, highlighting the challenges ahead as the battle moves into more densely populated neighborhoods where coalition air power must be used more selectively. (Photo by Felipe Dana/AP Photo)