Source- beginning of a river
mouth-end of a river
estuary- area there a river meet the sea or the ocean
tributary-river/stream that flows into another stream, river, or lake
The correct answer is - Eurasian and North American plates.
The Eurasian tectonic plate and the North American tectonic plate meet at the far east of Russia. In fact, the easternmost part of Russia actually belongs to the North American tectonic plate, and the boundary between these two plates is on land, not on water, like the political boundary between them. Because of this boundary, in the eastern part of Russia there's highlands that have formed because of the pressure, as the North American plate is moving slowly towards the Eurasian plate.
Answer:
C
Explanation: I learned this in 7th grade
The country Mongolia was like a buffer state between Russia and China. By definition, a buffer state is a country that's in between two countries or any powerful countries. Both countries sometimes come into agreement of occupying a certain part of the buffer state and can also cause war.
