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.
The oil extracted through these methods is referred to as "green crude" and it's not ready to be used as fuel until it undergoes another process called transesterification. This step adds more substances to the mix, including alcohol and a chemical catalyst that causes the alcohol to react with the oil. This reaction creates a mix of biodiesel and glycerol. The final step in processing separates the glycerol from the mixture and leaves a biodiesel that's ready to be used as fuel. Maybe one day it really will be easy being green.
You can read more about it here https://auto.howstuffworks.com/fuel-efficiency/biofuels/convert-algae-to-biofuel.htm
There are many forms of electromagnetic energy<span> including gamma rays, x rays, ultraviolet </span>radiation<span>, visible light, infrared </span>radiation<span>, microwaves and radio waves. </span>
Your teeth brake down down large food particles by chewing or grinding.