Promotional models use their smartphones during their break at the Global Mobile Internet Conference in Beijing May 6, 2014. Mobile Internet industry executives, developers and investors from more than 30 countries took part in the Global Mobile Internet Conference in Beijing, the organiser said. (Photo by Kim Kyung-Hoon/Reuters)

Zhang Jinduo's wife tries on a self-made racing car on the outskirts of Shenyang, Liaoning province May 10, 2008. Zhang, the 53-year-old local farmer made the racing car with the help of his son who is a car mechanic. The car is equipped with a rear-mounted motorcycle engine and can achieve 60-80 km per hour, according to local media. (Photo by Reuters/Stringer)

An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

A vendor smokes behind a display of dog meat at a dog meat market on the day of a local dog meat festival in Yulin, Guangxi Autonomous Region, June 22, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A pro-Russian rebel guards a captured former Ukrainian Army checkpoint outside Vuhlehirsk, Donetsk region, eastern Ukraine, Thursday, February 5, 2015. The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron. Separatists recently burst through government lines in the rural settlement of Vuhlehirsk. (Photo by Vadim Braydov/AP Photo)

A man holds a child after rescuing him from a kindergarten affected by a fire at a commercial building, in Ningde, Fujian province, China, September 16, 2015. According to local media, more than 260 people were evacuated due to the fire, which broke out Wednesday morning. No causalities have been reported and the cause of it is still unknown. (Photo by Reuters/China Daily)

Tokio Hotel fan Jennifer poses with Bill Kaulitz wax figure at Madame Tussauds on September 30, 2008 in Berlin, Germany. (Photo by Florian Seefried/Getty Images)

Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)