(251227) -- NANJING, Dec. 27, 2025 (Xinhua) -- This photo taken on Dec. 27, 2025 shows the rear of the "Xinzhengcheng" tunnel boring machine at the construction site of Nanjing Metro Line 4 Phase II, in Nanjing, east China's Jiangsu Province. A 3,062.6-meter-long double-track tunnel of Nanjing Metro Line 4 Phase II completed tunneling on Saturday. It is the deepest cross-river metro tunnel in the Yangtze River Delta region.
The Nanjing Metro Line 4 Phase II, with a total length of about 10 km, has six stations. (Xinhua/Ji Chunpeng)
