The principle difference between point source and nonpoint source water pollution is
a. whether the pollution is organic or inorganic
b. the number of sources of pollution
c. the amount of pollution
d. whether it is from commercial or agricultural sources

The principle difference between point source and nonpoint source water pollution is b. the number of sources of pollution. Point source pollution is caused by only one source of pollution and can be easily identified. Nonpoint source is composed of different sources.

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.