Answer:
Explanation:
Do you mean the solvent? If this is off the mark, let me know in a comment.
The solvent is something that the solute is (usually) soluble in.
The mechanical energy in the falling water is used to spin the generator, and gets transformed into electrical energy. That's the first choice on the list.
Scientific theory because it's a theory it's already an answer but it might change depending on the condition.
Gradpoint ? And the answer is water.