An aerial drone photo shows workers laying tracks at the construction site of Jiangjiaping bridge of the extension project of Weng'an-Machangping Railway in southwest China's Guizhou Province, March 31, 2025. The prefabricated T-beam and track laying of the 148-kilometer-long extension project of Weng'an-Machangping Railway was launched on Monday. (Xinhua/Yang Wenbin)