https://www.dropbox.com/s/4pygodda5tntm2u/lesson9-pollutions-140904220924-phpapp01.pptx?dl=1

7.  http://www.gogreencebu.com/burning-plastics-causes-us-to-suffer/
 http://www.ndimensionalgis.com/Services.htm
 http://www.lastormwater.org/blog/2011/09/8-pollution-prevention-tips/
 http://againstpollutioncetis44.blogspot.com/
 http://www.sritweets.com/pollution-affects-stone-alsopollution-problems/
 http://www.thepollutionfacts.com/2013/02/water-pollution-facts.html