Answer:
Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same.
Humans impact the physical environment in many ways overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.
What would most likely reduce the bias present in Elias' experimental design would be to not ask just the members of his high school team to be the subjects because they represent a very specific group of people. It would be much better to use a random group of people and have them do the same thing.
Hey there!
I do believe that your answer will be choice A
