Aquarium visitors attend a dinner party in an underwater tunnel in Tianjin, China on September 15, 2016. Tianjin Haichang Polar Ocean World opened in the city of Tianjin, southeast of Beijing, in 2010. It gives visitors a chance to see more than 150 large animals from the Arctic and Antarctic regions, including polar bears. (Photo by Feature China/Barcroft Images)

Russia's Ekaterina Birlova casts a shadow on the sand as she serves to Poland during a women's beach volleyball match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, August 9, 2016. (Photo by Marcio Jose Sanchez/AP Photo)

Show promoters for Motolite batteries sit on a jeepney as they pose for photographers during the Manila International Auto show in Pasay, Metro Manila, Philippines on April 4, 2013. (Photo by Erik De Castro/Reuters)

Pierre Thivillon (R), director of the zoological park of Saint-Martin-La-Plaine and his wife Eliane look at Digit, an 18-year-old female gorilla, on August 19, 2016, in Saint-Martin-La-Plaine between Lyon and Saint-Etienne, southeastern France. The zoological park of Saint-Martin-La-Plaine is a shelter for beasts seized by the justice. (Photo by Philippe Desmazes/AFP Photo)

A migrant labourer brushes his teeth in front of a scrapped helicopter model in Mumbai, India, April 13, 2016. (Photo by Danish Siddiqui/Reuters)

A youth dives into a crater filled with water in Aleppo's al-Shaar district, in this July 10, 2014 file photo. (Photo by Hosam Katan/Reuters)

Lazar and his sister Andjelka sit by a candle in their home in the eastern Serbian town of Majdanpek, December 4, 2014. Electricity workers in Serbia struggled through snow, ice and treacherous terrain on Thursday to restore electricity to an eastern town left shivering without power, heating or running water for a fourth day. (Photo by Marko Djurica/Reuters)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)