Define two classes of natural resources.

Biotic natural resources also include fossil fuels such as coal and petroleum which are formed from organic matter that has decayed. Abiotic: these resources come from non-living and non-organic material. Examples of these resources include land, fresh water, air, and heavy metals (gold, iron, copper, silver, etc.).

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

the answer is: reproductively

i think i spelled it wrong lol

anyways hope i

-lavira: )