well I think the answers you are looking for are:
1.) looked
2.) left
answer:
d
why:
it states in passage two that "As the plant and animal matter decays, it releases nutrients into the soil. Then, it is absorbed by the roots of living plants and turned into food for the plant." -also you spelled will wrong :)
C, a mystery because the sea holds many unknowns
If the bolded word is 'superfluous' then it would be the words after that would help to determine the definition.
