In your own words compare and contrast primary vs. secondary succession (you need to address the substrate and pioneer species)

in primary succession the soil is not readily present so, primary succession needs more time to get constitute and the soil is readily present in the secondary succession and hence it requires very less time.

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

i am going to guess that it is co2.