The answer is rock and mineral particles bcoz it is only option which is not living thing from start
<span>I believe the answer is C. Grasslands and forests do not have permafrost--present in tundra and taiga so A can be eliminated. B is not right because forests and grasslands definitely do not get TOO much rain, assuming they're not talking about tropical rain forests. </span>
Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Limiting factors are resources or other factors in the environment that can lower the population growth rate. Limiting factors include a low food supply and lack of space. Limiting factors can lower birth rates, increase death rates, or lead to emigration.
