It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal, and fecal debris. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water
Answer:
The answer is a) oil
Explanation:
Oil, especially in these areas, are abundant. In the past, these areas became wealthy because of oil.
Highwall mining is often used when excavating an open-pit mine becomes too expensive. There are many advantages over underground mining, including the fact that it is both more cost-effective and involves less lead time.