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)

The figure of an eight-year-old boy is seen inside a suitcase on a Spanish civil guard scanner screen at the border between Morocco and Spain's north african enclave Ceuta, Spain in this handout photo released May 8, 2015. A 19-year-old woman was arrested May 7, 2015 for the attempted smuggling of the boy, who was checked by medics and handed over to juvenile prosecutors office, according to authorities. (Photo by Reuters/Ministerio Del Interior)

Three Chinese soldiers at the time of a civil war in China. (Photo by General Photographic Agency/Getty Images). 1922

Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)

Children play in front of a brick factory on the outskirts of the northern Myanmar city of Mandalay on December 14, 2015. (Photo by Phyo Hein Kyaw/AFP Photo)

Tea garden workers carry sacks of tea leaves at Fatikchera tea garden estate on the outskirts of Agartala, India, May 10, 2016. (Photo by Jayanta Dey/Reuters)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

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)