Fish weighing over 80 kilogram is cooked in a hotpot during a food festival in Zhengzhou, Henan province, China, October 17, 2015. (Photo by Reuters/Stringer)

An aerial view shows the Amazon rainforest at the Bom Futuro National Forest near Rio Pardo in Porto Velho, Rondonia State, Brazil, September 3, 2015. The town of Rio Pardo, a settlement of about 4,000 people in the Amazon rainforest, rises where only jungle stood less than a quarter of a century ago. Loggers first cleared the forest followed by ranchers and farmers, then small merchants and prospectors. Brazil's government has stated a goal of eliminating illegal deforestation, but enforcing the law in remote corners like Rio Pardo is far from easy. (Photo by Nacho Doce/Reuters)

A mother prays for success for her child in the college entrance examinations at a Buddhist temple in Seoul, South Korea, November 12, 2015. About 630,000 students on Thursday sat for the annual exams that could lead them to one of the country's top universities. In South Korea, there is no higher achievement than to be accepted by a prestigious university. As a result, many students prepare for these entrance exams from an early age, often studying up to 16 hours a day for years to take this test. (Photo by Kim Hong-Ji/Reuters)

A flight deck crew prepares to launch a F18 Super Hornet from the deck of the USS Eisenhower off the coast of Virginia, December 10, 2015 in the Atlantic Ocean. US Defense Secretary Ash Carter visited the carrier with India's Minister of Defense Manohar Parrikar to demonstrate US Navy aircraft carrier flight operations. (Photo by Mark Wilson/Getty Images)

A child looks at window cleaners work while dressed in sheep (C) and monkey costumes, denoting animal signs of the Chinese zodiac calendar, during an event marking the upcoming end of the year at a hotel in Tokyo, Japan, December 21, 2015. According to the zodiac calendar, 2015 is the year of the sheep and 2016 is the year of the monkey. (Photo by Thomas Peter/Reuters)

Ukrainian President Petro Poroshenko gestures during a news conference in Kiev, Ukraine, June 5, 2015. REUTERS/Mykhailo Markiv/Ukrainian Presidential Press Service/Pool

A young girls holds a ballot during the Greek referendum in Athens on July 5, 2015. Greek voters headed to the polls today to vote in a historic, tightly fought referendum on whether to accept worsening austerity in exchange for more bailout funds, in a gamble that could see it crash out of the euro. (Photo by Aris Messinis/AFP Photo)

An Indonesian muslim woman walks on “sea of sands” as they prepare for Eid Al-Fitr prayer at Parangkusumo beach on July 17, 2015 in Yogyakarta, Indonesia. Muslims worldwide observe the Eid Al-Fitr prayer to mark the end of Ramadan and the beginning of the new month of blessing Shawwal 1436 Hijriah. (Photo by Ulet Ifansasti/Getty Images)