Which of the following statements is true?

natural energy resources are nonrenewable and are being depleted.
current fuels are not polluting the air.
mercury released into aquatic ecosystems comes from rock erosion.
the natural cycles of earth can clear up our current air and water pollution problems.

The natural cycles of Earth can clear up our current air and water pollution problems.

Explanation:

The natural cycles of Earth can clear up our current air and water pollution problems.

Yes it can happen but it will usually take time. The nature by itself is capable of finding back again the equilibrium; homeostasis. Air and water pollution are the result of an unbalanced nature, now a days mainly caused by the human.

If the human would stop polluting water and air, nature by itself, thanks to its energy flow would be able to find the balance back again. Pollution is nothing more than the excess of energy which has to be solved to recover the balance.

where is the scientific experiment?