a: groundwater ~
b: underground sponge
What:
"Groundwater is like a very large, saturated underground sponge made of sands and gravels. Water seeps through this sponge at varying rates, depending on the permeability of the sands or gravel (Figure 1). Water filters down through the soil until it reaches the aquifer."
A nice article is in the link.
Useful?
Writer:
LCC:
Where:
Date: Mar 31 2016 5:36 PM
# 9697 Critique Analogy