The cellular process diffusion does not require cellular blank to reach equilibrium

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

Describe the two types of vascular tissue

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere