3.A population of 820 insects lives in a 1.2-acre area. They gather nectar from a population of 560 flowering plants. The plants live in a
0.2-acre area. Which population has greater density, the insects or the
plants? Why?

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it

Because some people pollute water ans waste it

I'm soooo sorry but i can't answer but you can ask another professor