Through many years of controversy with our late associates, the Northern States, we have vainly endeavored to secure tranquillity, and to obtain respect for the rights to which we were entitled.
I'd say that the statement from FDR's speeches that uses parallel structure is C. American ships have been sunk; American airplanes have been destroyed.
Both of these independent clauses use the passive form of the verb - in the first clause, the passive form of the verb <em>to sink </em>is used, and in the second, of the verb <em>to destroy.
</em>A parallel structure means that throughout a sentence, the same form of words is used, and given that here both sentences have passive forms, I'd say C is the correct answer.<em>
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The correct answer is, "He fears Creon"
