both, you know that it's dissolved oxygen and biological oxygen demand right, read your textbook... BOD is effectively for the amount of organic wastes in the water
I am doing that same assessment now, for the possible sources of contamination you'd talk about human activities in the vicinity and yeah faeces haha
For the second part, testing for OD is different to testing for BOD, OD is adding iodine and then starch or winkler's method, and then the...
I would just talk about those influential people who guided adherents to moksha through their teachings (the whole liberation from birth and rebirth), and talk specifically about who established and contributed to the Bhakti movement and its influence on adherents.
Hey, is there any chance you could tutor in Lane Cove?
It would be for Mathematics 2U and chem in relation to practice calculations (like mols and dilution of acids etc as opposed to content) and if yes, how much would you charge p/h?