Answer:
A North American Union, by EU's example, would mean that the US, Canada, and Mexico will function as one in many ways. The borders will be open, both for economic actions and for free movement of people. While this may seem good at first sight, it will actually cause some major problems as well. The US and Canada will face a major population increase in a very short period of time. The people from Mexico will rush to move into these two countries because of better living conditions and more job opportunities, which in turn will cause massive depopulation in Mexico. On one side, Mexico will face major economic problems because of a sharp decline in its labor force, while on another side, the people in the US and Canada will face problems because there will be tens of millions of new laborers that will offer their services for lower wages. This will lead to tens of millions of people losing their jobs or not being able to find j
Explanation:
The correct answer is - They formed long ago, and erosion has beveled them to their present elevation.
The Appalachian Mountain Range is one of the oldest mountain ranges on the planet. They have formed in the Ordovician Period, around 480 million years ago. When they formed and were at their peak, the Appalachians were much larger and higher than what they are in the present. The reason for their decline in size is attributed to the erosion. The erosion is a process that removes the material from its original position. This process has been influencing, at different rates, the Appalachians for almost half a billion years. Even though the erosion is not a process that acts very quickly, when put the time that it influenced these mountains we will see that it managed to lower them significantly. That process continues in the present, and in the manner in which the continents are moving, there shouldn't be any force that will help lift up the Appalachians again, but instead they will continue to shrink until they are flattened in the distant future.
