Villagers cry for their relatives who were killed in an earthquake during a funeral in Longmen village, in Lushan county in southwest China's Sichuan province, on April 21, 2013. Rescuers and relief teams struggled to rush supplies into the rural hills of the area after an earthquake left at least 180 people dead and more than 11,000 injured. (Photo by Associated Press)

Tourists play at a beach covered by a thick layer of green algae in Qingdao, China, on July 3, 2013. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit China's Qingdao coast last month. More than 20,000 tons of such seaweed has been removed from the city's beaches. This has now become an annual summer event. (Photo by Whitehotpix/ZumaPress.com)

White whales and their trainers present a show for visitors at Harbin Pole Aquarium on January 7, 2014 in Harbin, China. Aquarium is one of the tourist highlights of Harbin, attract domestic and foreign tourists visit each year. (Photo by Lintao Zhang/Getty Images)

Costume actors to wait before the show at “Chian Tourism Day” Inauguration Ceremony in Ninghai Zhejiang Province on May 19, 2011 in Ninghai, China. Various activities in local famous historic sites are being held to mark the day “China Tourism Day” on May 19. (Photo by Lintao Zhang/Getty Images)

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)

An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

A performer in traditional costume waits for her turn to go on stage at Longtan park as the Chinese Lunar New Year, which welcomes the Year of the Rooster, is celebrated in Beijing, China January 29, 2017. (Photo by Damir Sagolj/Reuters)