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)

These horses are pictured in the Khentii province in eastern Mongolia during the Winter Horse Festival – where skillful horsemen gather to challenge the strength of their horses and show off their riding skills. Pictures were taken by Batzaya Choijiljav, a travel company director from Mongolia. Here: The fur of a horse ices up in the –40 cold of Mongolia. (Photo by Batzaya Choijiljav/Caters News)

This is the Legends Russian Series. Legends car exceeds new Porsche 911 power-to-weight ratio – it is 260 hp per ton with the car weight of 500 kg. It’s been designed in the USA by 600 Racing Inc, a subsidiary of Speedway Motorsport, the largest motorsport holding company in America with the annual turnover of $567,000,000. Khimki, Moscow region. February 11, 2012. (Photo by Alexey Petrov)

Workers demonstrate outside the factory of Hua Yang Printing Holdings Co Ltd on October 30, 2007 in Shenzhen of Guangdong Province, China. Over 1,000 workers of the company have blocked the 107 State Highway where the firm is located, to protest against their employer, who owed half a month's salary to the workers. (Photo by China Photos/Getty Images)

An inflatable snake hovers during a performance by the French street theater company Plasticiens Volants on September 4, 2011 in Berlin, Germany. The spectale, featuring gigantic flying inflatable fairy-tale creatures and performers on stilts and in costume was a part of celebrations for the 125th anniversary of the Kurfuerstendamm, known locally as the Ku'damm, a shopping boulevard. (Photo by Adam Berry/Getty Images)

This photo taken on February 1, 2018 shows a worker trimming the skin imperfections of a silicone doll at a factory of EXDOLL, a firm based in the northeastern Chinese port city of Dalian. With China facing a massive gender gap and a greying population, a company wants to hook up lonely men and retirees with a new kind of companion: “Smart” sеx dolls that can talk, play music and turn on dishwashers. (Photo by Fred Dufour/AFP Photo)

The land-robot “teleMAX” of German company telerob stands next to soldiers during a trial at the German army base on May 18, 2010 in Hammelburg, Germany. ELROB provides an overview of the current state of affairs in European unmanned system technology and to evaluate commercial off-the-shelf products for military use. It is to show what is feasible in robotics, to support technological developments in Europe, and to find solutions for the current military challenges. (Photo by Ralph Orlowski/Getty Images)