Cargo vessels enter the five-tier ship lock at the Three Gorges Dam, a gigantic hydropower project on the Yangtze River, in Yichang City, central China's Hubei Province, Jan. 7, 2018. The throughput at the ship locks of the Three Gorges hydropower project reached a record high of 138 million tonnes in 2017. The Three Gorges project is a multi-functional water control system, consisting of a 2,309-meter-long and 185-meter-high dam, a five-tier ship lock and 26 hydropower turbo-generators. The project generates electricity, controls flooding by storing excess water and helps to regulate the river's shipping capacity. (Xinhua/Zheng Jiayu)