The upper part (file) of this combo photo taken by Li Changyong shows passengers at a port linking Shenzhen and Hong Kong, south China. The lower part of the combo photo taken by Mao Siqian on Feb. 9, 2017 shows a cross-sea bridge of Shenzhen Bay. This year marks the 40th anniversary of China's reform and opening-up policy. Over the past four decades, Shenzhen has developed from a small fishing village to a metropolis. (Xinhua)