Labourers pour molten iron into a container at a foundry in Xiangfan, Hubei province in this July 2, 2010 file photo. Iron ore is enjoying its biggest rally in years, outpacing copper and oil so far in 2016, but still weak forward prices show it may be tough to stretch the bullish outlook. Improving steel prices in top market China are helping fuel iron ore's climb as producers gear up for a seasonal uptick in demand. Yet there is no shortage of doubters who see gains in the bulk commodity as fleeting given a large glut and challenges for China's economy. (Photo by Reuters/Stringer)

Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)

A woman takes a picture of a Maserati's SUV model Levante during the Auto China 2016 show in Beijing, China April 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Performers dressed as Ded Moroz, the equivalent of Santa Claus, and his granddaughter Snegurochka (Snow Maiden) take on shoe covers as they visit the Republican Scientific and Practical Centre of Pediatric Surgery in Minsk, Belarus, December 28, 2016. (Photo by Vasily Fedosenko/Reuters)

A horse- drawn carriage rides along the race course through the Thuringian Forest in Oberhof, Germany, 05 January 2017. Winter found its way to Saxony, Saxony- Anhalt, and Thuringia. In some regions it can get as low as negative 20 degrees overnight. (Photo by Martin Schutt/Zentralbild/DPA)

A Kevo smart lock is demonstrated during the 2015 International Consumer Electronics Show (CES) in Las Vegas, Nevada January 4, 2015. The lock, which opens with a smart phone App and a touch, is smart enough to know what side of the door you are on and won't accidentally unlock the door when you are inside. A new subscription service offers unlimited e-keys and other benefits, a representative said. (Photo by Steve Marcus/Reuters)

Izzy Paskowitz helps Nixee Grace Chanowsky, 4, catch a wave Monday, August 18, 2014 at Wrightsville Beach, N.C. during the Annual Surfers Healing event for children with autism. Hundreds of people made their way to the beach to watch and cheer on the camp that was founded by Israel and Danielle Paskowitz. (Photo by Mike Spencer/AP Photo/The Star-News)

Google's vice president Alan Eustace looks out of his spacesuit into the stratosphere prior to a record-breaking skydive over New Mexico, in this still image taken from video October 24, 2014, a handout courtesy of the Paragon Space Development Corporation. Eustace was lifted up 135,890 ft (41,420 metres) by an enormous balloon while wearing a specially designed pressurized space suit, the Paragon Space Development Corporation said. Eustace remained in a free fall for approximately 4.5 minutes before landing safely nearly 70 miles (43.4 kms) from his launch point, setting a world record for the highest skydive and breaking the sound barrier in the process. Eustace landed safely on the ground just 15 minutes after he was lifted into the air. (Photo by Reuters/Paragon Space Development Corporation)