In some places, especially some new wells that have just been drilled,
the oil is under pressure, and it brings itself to the surface as soon as
you drill a 'pipe' for it to rise through.
In most oil wells, there's a pump bobbing up and down day and night,
pumping the oil up out of the well.
When the well is so old that even a pump isn't very effective, water is
often forced down the well under pressure, and the water forces the
oil back up through the pipe.
Causes:
1. the increase in population and growth of the human race
2. the need for housing and industrial advancements
effects:
1. loss of habitat for wildlife
2 loss of trees for oxygen
Cyanobacteria convert nitrates from the water into nitrogen gas (N2<span>) that is released into the atmosphere</span>
Answer: The basic theme of whale evolution is the development of large animals from much smaller ancestors, and nowhere is this more evident than in the case of multi-ton sperm and gray whales, whose ultimate forebears were small, dog-sized prehistoric mammals that prowled the riverbeds of central Asia 50 million years ago. Perhaps more intriguingly, whales are also a case study in the gradual evolution of mammals from fully terrestrial to fully marine lifestyles, with corresponding adaptations (elongated bodies, webbed feet, blowholes, etc.) at various key intervals along the way.
Explanation:Pick B is the best choice
