Aerial photo taken on April 11, 2021 shows the Wormhole Library in the Haikou Bay in Haikou, capital of south China's Hainan Province. Haikou, an important city of China's "Belt and Road" initiative and also a core city for the construction of free trade port in Hainan Province, will greet the first China International Consumer Products Expo. (Xinhua/Zhang Liyun)
