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Earth's mass has remained constant, and thus the gravitational pull at the surface has decreased over time; Earth's mass has grown with the volume in such a way that the surface gravity has remained constant; Earth's gravity at its surface has increased over time, in line with its hypothesized growing mass and volume.
Federalism is the system of government in which power is divided between a central government and regional governments; in the United States, both the national government and the state governments possess a large measure of sovereignty.
<span>During WW I the government implemented price controls and rationing. The correct option among all the options that are given in the question is the third option or option "c". The other choices are incorrect and should be neglected. I hope that this is the answer that has actually come to your desired help.</span>