Answer:
Explanation:
Most limestones actually start as calcium carbonate mud or shells precipitated by organisms in reefs or shallow shelf regions - the biosphere. Over time, the limestone is broken down into its chemical parts and may come back to the surface as volcanic CO2 (in the atmosphere).
Answer:
Cells are so little, so they can maximize their ratio of surface area to volume.
Explanation:
Smaller cells have a higher ratio which allows more molecules and ions to move across the cell membrane per unit of cytoplasmic volume. Cells are so small because they need to be able to get the nutrients in and the waste out quickly.
Answer:
The right atrium takes blood from the veins and pumps it into a ventricle
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