Water Resources

2. makes up about 97% of the water supply
3. we have been buying water from this country since the 1920s
6. the process of water filtration used in desalination
7. produced when impurities are removed from the waste water
9. occurs when there is a shortage of water
10. much of the world's water supply is used in_______and in agriculture
11. it is important for life on Earth
13. the method used in Singapore to increase the supply of fresh water
15. when there is insufficient supply of water for people
17. the process of forcing water through a special membrane to remove small particles from water
19. the process of filtering water to remove larger particles and bacteria from the water
20. the careful use of resources to ensure that wastage is kept to a minimum

1. the process of converting sea water into fresh water
4. an area over which the rain falls and is collected
5. an arrangement between two counties for supply and use of water resources for a certain period of time
8. this is produced in reverse osmosis
12. this makes up 1% of the freshwater
14. the knowledge and tools that people use to meet their needs
16. this means 'can ran out one day'
18. these campaigns have been carried out to show the importance of water