I believe that the answer is B.
Answer:
vestigial structures are considered evidence because scientists believe they are structures that were once used by a species ancestors but are not longer needed. these structures do not impair the organism in any way, so there is no need for evolution to get rid of them. for example, the human appendix is considered a vestigial structure.
Explanation:
:D
Answer:
molecule
Explanation:
because water aka h20 is a molecule
Because proteins are complex molecules, the body takes longer to break them down
Over time, as oxygen levels decrease, CO2 levels increase. Respiration is correct as it uses oxygen as a reactant and releases CO2 as a byproduct.