Answer:A. differing densities of the elements that make up the Earth.
Explanation: The densities of the different materials making up the Earth surface and the Earth crust, due to the varying density of these materials it makes it difficult to break certain types of materials.
When the time required to break down materials differ,the earth's surface will have different layers caused by the time difference between the breakdown of these materials.
The more the density of the material the more difficult it is to break it down.
Well the actual year is 2011 so the answer is D
What are the options for the question?
Answer:
tectonic plates are floating on top of the molten rock and moving around the planet like leaves on water. they bump into each other or move away from each other
geography4kids
when converging plates will move beneath the other its subduction
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