One-year-old female giant panda cub Nuan Nuan reacts inside her enclosure during joint birthday celebrations for the panda and its ten-year-old mother Liang Liang at the National Zoo in Kuala Lumpur on August 23, 2016. Giant pandas Liang Liang, aged 10, and her Malaysian-born cub Nuan Nuan, 1, were born on August 23, 2006 and August 18, 2015 respectivetly. (Photo by Mohd Rasfan/AFP Photo)

A general view of the sunrise over Hawes, Wensleydale, UK on November 24, 2014. (Photo by Neil Squires/PA Wire)

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

Pedestrians have a snowball fight in Times Square following a mandatory shutdown of the streets at 11 p.m. on January 26, 2015 in New York City. New York, and much of the Northeast, is bracing for a major winter storm which is expected to bring blizzard conditions and 10 to 30 inches of snow to the area. (Photo by Alex Trautwig/AFP Photo)

Recycling artist Nicolas Gomez checks the strings of a cello he has made out of an oil barrel for the Orchestra of Recycled Instruments of Cateura, in Cateura, Paraguay February 13, 2015. Saudi Arabia's oil exports have risen in February in response to stronger demand from customers. As OPEC's top producer battles for market share Reuters photographers around the globe have been photographing oil barrels to document how they are utilised once the fuel has been used. (Photo by Jorge Adorno/Reuters)

A sales woman of a fish shop shows king crabs to a customer and negotiates the price in Noryangjin Fish Market is seen on August 1, 2015 in Seoul, South Korea. Noryangjin Fish Market was established in 1927 as Gyeongseong Susan in Jung-gu near Seoul Station and moved to its current location in 1971. (Photo by Shin Woong-jae/The Washington Post)

Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)