Why are the continental divide and the fall line two important physical features in the united states?

The continental divide is important because it determines which direction rivers flow from their headwaters since it is at this divide point that water either flows one way or another so this explains where the important rivers flow ie say the Mississippi or Missouri. The fall line is where two parallel rivers drop down from a height of land so most likely would prevent navigation of the river at this point.

Where exactly from michigan?

That is false the sun’s core does not fusion