A B (a) recharging with rainwater (b) make water potable (fit for drinking) (c) a kind of filtration device (d) used for drinking and agriculture Ans. 1.______, 2., 3. 4. Jeevandeep Water Security Workbook & Activity - Project Book - Std. 9 (31) 1. Coal filter 2. Groundwater reserves 3. rainwater harvesting 4. liquid chlorine or tablets​