The answer would be , the sum of all genetic traits in a population’s individuals at any given time
Occurs naturally on earth
Answer:
She could time how long it takes for each amount of salt dissolves in the waters. (as well as keep each amount of salt the same if she was not doing that already.)
Explanation:
This way, she could observe which water is best for dissolving solvents and which is most affective in the shortest amount of time. If she was not timing how long it takes for salt to dissolve in different temperatures of water, then the experiment may as well have been useless unless there is somehow a different objective.
I think your anwser would be all of the above but you don't have it