Which of the following are not removed from the oil during the refining process? Select one:
a. Sulfur
b. Hydrocarbons
c. Nitrogen
d. Oxygen

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.