<span>Distribution of mineral deposits would be the answer since 'economy' deals with deposits as the rest of the answers deal with weathering and they don't include an economics. </span>
The 2 plates that make up the great rift valley is the African plate and the Arabian plate.
<span>first thing you need to do is find the area of the circle
A=(pi)r^2
You don't know r, but you do know the diameter is 10, and the diameter is twice the radius so r=5
Then plug that into the area formula, and you'll get A=25pi or 78.54 ft^2
If one bag covers 2 ft^2, then divide your area by 2 and round up to get the number of bags of concrete (40)
hope i helped !!!</span>
Answer: a swamp
hope this helps!!
