Is it true or false that some ecosystems can recover after a disturbance

Several kinds of bears are found on earth. most bears are brown or black, but one type of bear, the polar bear, is white. what process led to this difference in fur color? explain your answer.

What is the common name for the compound shown here? enter the common name of the compound shown?

Aman applies a force of 500n to push a truck 100m down the street how much does he do?