Problem: Given the question: What is the final step of the following process: -  Pollution enters natural water sources such as rivers and lakes - The pollution negatively affects the water quality - The pollution negatively affects the health of plants and animals - The plants and animals have shorter, less healthy lives - The plants and animals do not reproduce very well - The number of plants and animals decreases over time - The quality of water gets worse and worse as there are no plants or animals to clean it
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The answer is:
Eventually there is nothing living in the water and it is unusable


Problem: Given the question: What is the final step of the following process: -  Blood is sent to the liver - The liver uses chemicals and proteins to treat the blood - The blood is cleaned - Energy is produced
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The answer is:
The blood leaves the liver cleaned.


Problem: Given the question: What is the final step of the following process: -  Living organisms in the sea die - The matter forms on the sea floor - Layers of sediment form above the matter compressing it - After many years the matter is compressed and heated
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The answer is:
