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.
Answer:
Plants are autotrophs because they can prepare their own food. Photosynthesis takes place in leaves. Leaves contain stomata that allow for the exchange of gases during the process, and also help with the process of transpiration.