Through river basins, and administrative boundaries to protect their natural water resources.
I think it's A but here's an explanation anyway: as you heat the crude oil, the different hydrocarbons, having different boiling points, boil and evaporate up the column. Those with lower boiling points, shorter in chain length, will condense nearer the top of the fractional distillation column. Those that are more viscous, larger in chain size, will have high boiling points, so will evaporate last and condense lower down in the column. Therefore, you achieve all the different oils / materials (oil, petrol, gasoline, tar etc etc). I hope this helps. If not, then a good website to use is 'BBC bitesize, fractional distillation'.
Answer:
A vertebrate is an animal or species distinguished by its possession of a backbone or spinal column. Vertebrates can be insects, fish, mammals, birds, reptiles, and also amphibians.
Hope this helps :)
Answer:
the earth rotates about it's axis,just as a top spins around it's spindle.the earth rotates from the north pole to the south pole.it takes 24hours for the earth to make one complete rotation.
I hope this helps
A. in the interior lowlands
It's in Nevada in U.S.
