试题出自试卷《2017年6月大学英语四级真题（第1套）》

The Yangtze River is the longest river in Asia and the third longest, river in the world. It flows through a wide array of ecosystems and is the habitat for many endangered species. The Yangtze River irrigates one-fifth of the land area of China and its river basin is home to one third of the country’s population. The river plays a significant role in the history, culture and economy of China. The Yangtze River Delta generates as much as 20% of China’s GDP. For thousands of years, the Yangtze River has been used for water supply, transportation and industrial production. The world’s largest hydro-electric power station also sits on the Yangtze River.