Answer:
the answer is two for this question
The word sponge is more appropriate to use than Underground river since an underground river can loose water while an aquifer cannot loose water, unless it is open-air and above ground. then the aquifer would slowly loose water due to evaporation from the sun.
By soil parent material type is understoodunconsolidated deposits (regolith) found on the bedrock. Most Soil parent materials are made up from weathered and disintegrated rock material.
I'm sorry, but is this a question? I'm a bit confused.
