Why is freshwater essential to human life?

Which of the following describes a boom period? a. as one population increases, another population decreases. b. as one population increases, the other population also increases. c. as one population decreases, another population increases. d. as one population decreases, another population also decreases

What would happen if the tubing with the yellow band was placed in a beaker of distilled water?

In general, are there any major differences that you can see? explain