Aerial photo taken on Dec. 27, 2019 shows the newly-built section of the Wenchun-Maerkang expressway in Aba Tibetan and Qiang Autonomous Prefecture, southwest China's Sichuan Province. A 43-kilometer section of the Wenchun-Maerkang expressway in Aba Tibetan and Qiang Autonomous Prefecture was open to traffic on Tuesday. Till now, the mileage of the expressway opened to traffic has been up to 148 kilometers. (Xinhua/Liu Kun)