Answer:
The Earth also gives us clues about the levels of greenhouse gases that existed in the past. For example, ancient air bubbles trapped deep in the ice of Greenland and Antarctica reveal how much carbon dioxide was present long ago.
Explanation:I learn it in 8 grade.
Rivers provided food and fresh water, as well as fertile soil that would be suitable for growing basic crops.
The Mongols set up a tribute empire called The Golden Horde. Serfdom arose as peasants gave up their lands to the aristocracy in exchange for protection from the Mongols. Moscow benefited financially by acting as a tribute collector for the Mongols. Mongol rule kept Russia culturally isolated from Western European trends such as the Renaissance.
Explanation: What are you talking about here is it about the exports imports? Is it about their valubale resources. Please elaborate.