Answer:
Coal is a fossil fuel. It comes from the remains of plants that died about 100 to 400 million years ago. Coal is a non-renewable energy source because it takes millions of years to form
Kidney stones are stones caused by the precipitation of minerals, such as calcium, and other substances from the urine or kidney filtrate.
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What are Kidney stones?</h3>
These are hard deposits of minerals such as calcium etc which stick together in the urine of affected individuals.
This thereby causes pain when urine is being expelled from the body as a result of the large size.
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They are like that because they can't always be faulty and may have at least some spark of truth to this theory also as stated earlier a theory in scientific terms is just an observation so it can't really be turned down hence theory.
Process which by plants and animals break down sugar and turn it into energy.
Purpose is it provides cells with the energy they need to function.
