<span>The correct answer is option D.An ecosystem consists of a population of organisms and its physical environment, and a population is made up of many different communities of organisms. An ecosystem is a bilogical system of populations and environment. And a population consists many communities and finally the communities are nade up of organisms.</span>
A single fundamental similarity and or unity among all living organisms, is that all living organisms are composed of the basic units is life known as cells.
A ...because it lets more people share resources
There are about 250 chemicals that are harmful including carbon monoxide and ammonia.