7月24日，科考队员在为“探索”号做下潜前的准备。当日，我国自主研发的自治式水下机器人“探索”号在南海北部开展首次试验性应用，预计水下作业时间20小时。[新华社 张旭东 摄]
Scientific researchers make preparation for the first experimental operation of the country's self-developed underwater robot in the South China Sea, July 24, 2017. It is expected to stay underwater for 20 hours. (Xinhua/Zhang Xudong)