Time distance decay
Hope it helps :)
The seismic wave can tell the scientists about the earth's layers.<span />
B, provide systematic irrigation.
The "policing of the Western Hemisphere" is a phrase that conveys Roosevelt's attitude when it came to international affairs. Roosevelt believed that the United States was justified in exercising this policing for several reasons. He argued that there had been chronic unrest or wrongdoing in the Western Hemisphere for a very long time, and someone had to put an end to it. Moreover, he stated that the United States would intervene in conflucts between European countries and Latin American countries if the European powers had a legitimate claim. He argued that this attitude would work because it came hand in hand with the Monroe Doctrine. While the Monroe Doctrine was meant to put an end to European intervention, the "corollary" (which stated the US intention to police the hemisphere) was used to justify American intervention.
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.
