Eight percent of the Earth's crust is aluminum, and there are hundreds

All correct in 3.5 mins!

Meaning of the passage - Sources of Aluminium or Alumnia (intermediary component)

1. The author implies that a mineral must either be or readily supply which of the following in order to be classified as an aluminum ore?

(A) An aggregate
(B) Bauxite
(C) Alumina - Correct, Aluminia is an intermediary product that is essentially required to make aluminium
(D) Corundum
(E) An aluminum silicate

2. The passage supplies information for answering all of the following questions regarding aluminous minerals EXCEPT:

(A) What percentage of the aluminum in the Earth's crust is in the form of bauxite? - Correct. The passage states the percentage of "Aluminium" and not bauxite
(B) Are aluminum-bearing nonbauxite minerals plentiful?
(C) Do the aluminous minerals found iIi bauxite contain hydrated oxides?
(D) Are aluminous hydrated oxides found in rocks?
(E) Do large quantities of bauxite exist?

3. The author implies that corundum would be used to produce aluminum if

(A) corundum could be found that is not contaminated by silicates
(B) the production of alumina could be eliminated as an intermediate step in manufacturing aluminum
(C) many large deposits of very high-quality corundum were to be discovered - Correct, Corundum is less efficient/rich in Aluminia (intermediary). Hence, having an aluminia rich corundum would efficient for producing Aluminium.
(D) new technologies were to make it possible to convert corundum to a silicate
(E) manufacturers were to realize that the world's supply of bauxite is not unlimited