Why is artificial erosion a concern if erosion can occur naturally? a. artificial erosion changes environments while natural erosion does not. b. artificial erosion occurs at a faster rate than natural erosion. c. artificial erosion affects soil while natural erosion does not. d. artificial erosion is of no concern.

The correct answer is(b) Artificial erosion occurs at a faster rate than natural erosion.

The difference between the natural and artificial erosion is that natural erosion is gradual removal of upper layer of soil but artificial erosion is fast removal of upper layer of soil which is not beneficial for the environment. The environment has its own ways of stabilizing the effects of natural erosion but in case of artificial erosion it can be harmful for the nature as it is very fast.  

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate