A seafood vendor moves a giant swordfish to his stall at a market in Qingdao, Shandong province, China, September 12, 2015. The 4.1-metre-long (13.5 feet) swordfish, weighed about 309.5 kilograms (682 lbs), was caught by local fishermen on Friday, local media reported. (Photo by Reuters/Stringer)

Local villagers ride a local coal powered steam train on March 27, 2015 at a station in the town of Shixi , Sichuan Province, in Southern China. While China boasts the world's most extensive high-speed rail infrastructure with over 16,000 kilometers of track, the Shixi-Bagou railway is still a primary connection for local villagers between towns and is kept alive by tourist cars carrying passengers for ten times the price. The rail line came into service in the late 1950s and the train was initially used to transport coal from a now-shuttered mine before passenger carriages were added. (Photo by Kevin Frayer/Getty Images)

A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

Young Chinese football players help an injured player off the field during training at the Evergrande International Football School on June 12, 2014 near Qingyuan in Guangdong Province, China. The sprawling 167-acre campus is the brainchild of property tycoon Xu Jiayin, whose ambition is to train a generation of young athletes to establish China as a football powerhouse. The school is considered the largest football academy in the world with 2400 students, more than 50 pitches and a squad of Spanish coaches through a partnership with Real Madrid. (Photo by Kevin Frayer/Getty Images)

Visitors walk through a tulip display in Chaya Mountain, Suiping County in Zhumadian, Henan Province of China on March 31, 2016. There are more than ten varieties of tulips here. (Photo by VCG/VCG via Getty Images)

A paramilitary police officer (right) turns around as hostesses line up for roll call ahead of the Beijing International Automotive Exhibition in Beijing, China, on Monday, April 25, 2016. Tesla Motors Inc. and BYD Co. are among manufacturers showing 147 new-energy vehicles at this year's show. (Photo by Qilai Shen/Bloomberg)

A train attendant helps a passenger to adjust her seat at the business class carriage on a CRH 380A bullet train Thursday, June 16, 2011. (Photo by Reuters/China Daily)

A man in “Red Army” garb hits the pavement during a simulated attack during a re-staging of part of the Long March in Jinggangshan September 14, 2017. The scene brings alive an extraordinary chapter in China's history that established the supremacy of Chairman Mao Zedong and the Communist Party. Deep in the mountains of Jinggangshan in the southeastern province of Jiangxi, a classroom of bank tellers participates in an ideological boot camp that plays into Chinese President Xi Jinping's drive to further consolidate his grip on power. (Photo by Thomas Peter/Reuters)