The two are blood and lymph
I think carbon and hydrogen.
Answers/ Explanations:
- Water is considered a <u>'Natural'</u> resource (Fresh water is also considered a <u>'limited'</u> resource.
- Oil, coal, and natural gas are considered <u>'Non-renewable'</u> resources.
- <u>'Chemical'</u> energy is able to be replaced within the ecosystem for human use.
- A farmer who wants to produce the best crop yield will use '<u>Precision Farming.'</u>
- When a pollutant increases in concentration at higher levels of the trophic level, <u>'Biomagnification'</u> can harm organisms at the highest levels.
Answer:
Shape of Red Blood Cells Erythrocytes are biconcave discs with very shallow centers. This shape optimizes the ratio of surface area to volume, facilitating gas exchange. It also enables them to fold up as they move through narrow blood vessels.