If the students want to select particular trials to test further in order to ultimately choose the best design, which should be tested to help with the refining process? Select two that apply

According to the passage, which of these is true about gray water systems? a) gray water systems use plants that require less water. eliminate b) gray water systems require the use of less fossil fuels. c) gray water systems reduce the amount of fresh water used. d) gray water systems reduce the amount water used by shower heads.