Photo taken on Dec. 9, 2018 shows the construction site of a railway arch bridge across the Nujiang River in southwest China's Yunnan Province. With a grand arch bridge erected on Monday morning, Chinese constructors have built the longest-spanning railway arch bridge with a single span of 490 meters. The bridge is a key project of the 220-km-long Dali-Ruili railway which is a key section of the China-Myanmar international railway corridor linking Kunming, the provincial capital of Yunnan, with Yangon of Myanmar. [Photo/Xinhua]