(250227) -- BEIJING, Feb. 27, 2025 (Xinhua) -- Workers are pictured at the construction site of the Beijing sub-center comprehensive transportation hub in Tongzhou District, sub-center of Beijing, capital of China, Feb. 26, 2025. The construction of the Beijing sub-center comprehensive transportation hub, Asia's largest underground transportation complex, is proceeding smoothly. The hub will link cross-regional and intercity railways, and several metro lines when completed as scheduled by the end of 2025. (Xinhua/Ju Huanzong)