This aerial photo taken on May 24, 2016 shows the night view of West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 24, 2016 shows the night view of the West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on April 11, 2016 shows the forest near Yanggongdi at the West Lake scenic spot in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on Sept. 8, 2015 shows an eight diagrams field in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 24, 2016 shows the Xixinghutong overpass on the airport highway in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on Sept. 17, 2015 shows the Qiantangjiang Bridge and the Liuhe Tower in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 12, 2015 shows the West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 24, 2016 shows the night city view of Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 11, 2016 shows the Huxin Island at the West Lake scenic spot in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on Sept. 16, 2015 shows the Hangzhou Olympic Sports Center in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 24, 2016 shows the night view of the West Lake Cultural Square in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on March 20, 2015 shows farmers picking spring tea leaves at a Longjing tea garden in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 11, 2016 shows the Baidi at the West Lake scenic spot in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on Nov. 3, 2015 shows the autumn scenery of the Xixi wetland park in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 17, 2016 shows the Qiantang River in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 12, 2016 shows the wetland of West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 8, 2016 shows the Huanglong Stadium in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on Feb. 11, 2016 shows the Broken Bridge of West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on May 24, 2016 shows the musical fountain of West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua

This aerial photo taken on July 9, 2014 shows the Broken Bridge of West Lake in Hangzhou, capital of east China's Zhejiang Province. China will host the 2016 Group of Twenty (G20) summit in the eastern city of Hangzhou, a tourism city best known for its West Lake scenic spot, on Sept. 4-5. Photo: Xinhua