Abasic source of pollution is from unnatural sources and people. true false disturbance of the natural environment often produces "blank" results. a) unexpected b) predictable c) minimal d) expected the best word to describe a group of microorganisms which float on water is: community ecosystem food chain environment ideally, an inventory of an ecosystem should be taken: before a problem is suspected as soon as a study is needed when species may be in danger of extinction all of the above