Aerial photo taken on Sept. 5, 2021 shows the construction site of Nanquan section of Taihu tunnel, part of the Changzhou-Wuxi Highway, in Wuxi, east China's Jiangsu Province. The main construction of the Nanquan section of the Taihu tunnel was completed on Sunday. Taihu tunnel, China's longest underwater highway tunnel, is part of the Changzhou-Wuxi Highway which has a total length of 43.9 km. The 10.8-km-long, 43.6-meter-wide tunnel is under Taihu Lake, China's third-largest freshwater lake. (Xinhua/Li Bo)