Please - Need Quick answer for Brianliest :) Fill in the blank

A community in which multiple organisms interact and depend on one another for balance is a(n) which also depends on the of both matter and energy.

When should a bar graph be used? a. when there is no independent variable. b. when the independent variable is continuous and does not show a relationship to the dependent variable. c. when the independent variable is continuous and shows a causal link to the dependent variable. d. when the independent variable is composed of categories and does not show a relationship.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

According the inverse square law, doubling the distance from the source of the sound, a speaker, for example, will drop the sound 6 db each time. if you were standing in the back of an auditorium, 32 feet away from a speaker not using any amplification, would you be able to hear a speaker clearly? why or why not?