These areas are created when land erosion and a high water table have allowed some of the water to percolate to the surface.

The appropriate response is Oasis. It is shaped from underground streams or aquifers, for example, an artesian aquifer, where water can achieve the surface normally by weight or by man-made wells. Periodic brief rainstorms give underground water to manage common desert gardens, for example, the Tuat. Substrata of impermeable shake and stone can trap water and hold it in pockets, or on long blaming subsurface edges or volcanic barriers water can gather and permeate to the surface.

H=   2(area/a+b)h= 2(144/a+b)h= 2(144/18+18)h= 2(144/36)h= 2(4)h=8

980 is the correct answer