Answer:
B
Explanation:
Reservoir B is labeled as sentence Organic materials unavailable as nutrients. It contains a factory emitting smog into the air, and layers described from top to bottom as peat, coal, and oil.
Building blocks of cell membranes, insulation, cell communication, energy storage, protection
Answer:
Left atrium
Explanation:
The four pulmonary veins return oxygenated blood to the left atrium.