What did Aristotle believe? O A. That the scientific method should be used to test ideas
OB. That all matter was composed of earth, fire, water, and air
O c. That matter did not exist in the physical world
O D. That all matter was composed of tiny atoms

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.