Aerial photo taken on Aug. 26, 2020 shows the Liantang Port/Heung Yuen Wai Boundary Control Point at the Hong Kong-Shenzhen boundary in south China. Known as a paragon of opening-up and development, Shenzhen in Guangdong Province is one of China's earliest special economic zones. Starting from a small town, it has developed into a key economic hub in the past 40 years. (Xinhua/Mao Siqian)