Read the sentence, looking for clues
"Prodigious" means "very large." If the costs are huge, what would be their
effect, were it not for the bounty (or abundance) of oil?
Predict an answer
They would make the operation unprofitable, so look for a word with that meaning
in the answer choices.
Select the choice that most closely matches your
prediction
If there weren't money to be made from the oil, the costs would be (C) prohibitive; they'd prohibit, or "prevent", the oil companies from
making a profit. This is the correct answer. (A) stupendous and (D) immeasurable would both be synonyms for "prodigious"; however, the
blank isn't describing the profits themselves but their effects. Furthermore, since
they mean the same thing in this context, there's no way to pick one over the other,
so they both must be wrong. (B) profitable is the opposite of what's needed. (E) commensurate means "equivalent to" or "the
same as"; with nothing to complete this comparison, this doesn't work.
Check your answer
The costs of building, manning and maintaining the giant oil rigs of the Canning
Basin are so prodigious that they would be prohibitive were there not such a bounty of oil to be
extracted.
TAKEAWAY: When two synonyms show up as choices for the same blank in Text
Completion, both can be eliminated. There's no way to pick one over the
other.
