Which of the following is the best model to help explain how light behaves as it passes from air and then through a piece of transparent glass? Use evidence and scientific reasoning to support your answer. (It's very important)

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.