Answer:
The Mongols. (Genghis Khan, so on, so on.)
Explanation:
When the Mongol Empire was per se at its peak, the Mongols had controlled much of Eastern Europe and the majority of mainland Asia. This meant they controlled The Silk Road, the many trade routes between Europe and China.
The correct answer is C. A decrease in hydropower development.
The Yangtze River is one of the longest rivers by volume in all the world. And it has become the river which flows entirely in the country. What makes this river to have less pollution is the fact that there are some parts that are protected as nature reserves.
