Question

Oil _____.

Answer 1

Answer: The correct answer for the blank is -

must be mined from underground.

Oil is considered as a fossil fuel as it is formed by the dead remains of plants and animals that lived on earth millions of years back.

It is a non renewable source of energy because it can not be replenished readily by natural means and to renew, it would again require millions of years.

Mining of oil is a process of extraction  of fossil fuels from underground, which is based on the digging of underground mining excavations.

Thus, oil must be mined from underground is the right answer.

Answer 2

Oil must be mined from underground 

Oil is NOT a renewable resource
Oil does NOT release more toxins than coal
Oil also is NOT easily replenished