answer of the question: B
Decomposition- the break down of dead organisms.
Answer:
<em>Open </em><em>circulatory </em><em>system</em><em> </em><em>is </em><em>the </em><em>system </em><em>that</em><em> </em><em>is </em><em>primarily</em><em> </em><em>found </em><em>in </em><em>invertebrates.</em>
Answer:
It helps them figure out what was in the area thousands of years ago