Answer: Plate motions cause mountains to rise where plates push together, or converge, and continents to fracture and oceans to form where plates pull apart, or diverge. The continents are embedded in the plates and drift passively with them, which over millions of years results in significant changes in Earth's geography.
Answer: 1917, two revolutions swept through Russia, ending centuries of imperial rule and setting into motion political and social changes that would lead to the formation of the Soviet Union.
