Visitors look at the model of the China's manned submersible Jiaolong at the 2019 China Marine Economy Expo in Shenzhen, south China's Guangdong Province, Oct. 15, 2019. The expo, under the theme of "Sharing Blue Economy Opportunities, Building a Shared Future," opened here on Tuesday. It has attracted more than 450 companies and institutions to participate and is expected to present China's achievements in the marine economy and the latest progress in the global marine industry. (Xinhua/Mao Siqian)