Answer:
B. a nucleus
Explanation:
cell walls and chloroplast are both found in plant cells, not in animal cells
B .The membrane is what separates, and is the system boundary.<span />
Answer:
Chemical, cellular. tissue, organ, organ system, and organism level.
Explanation:
Carbon dioxide
carbon monoxide
sulfer dioxide
Answer:
They are solid at room temperature. They include a carbon single bond.
Explanation:
Look at this image- hope it helps. Because of the fact that they are not bent, they are packed tightly and solid, not liquid.