Writing Question! (Help!)

<p>I just finished taking a practice test and I got 2 wrong ont he Writing sections.
I got the other one, but I did not get this one:
(Identifying Sentence Error)
Forest fires, long thought to be a detriment to the environment, are now understood not only to be unavoidable but also to be a boon to the forests.</p>

<p>A) thought to be
B) are
C) not only
D) a boon
E)No Error</p>

<p>I chose D) a boon because of the "are" earlier in the sentence and the fact that "forest fires," in my opinion, is plural. However, the answer is No Error. Can anyone explain this to me? I mean, in the appositive, it implies that "forest fires" are singular with the "a detriment" while giving "are" and "a boon," which contradicts. :$</p>

<p>This is 22, Section 7 on test 2 of Princeton Review.</p>

<p>“A boon” works just like “a present.” </p>

<p>Do you agree that this sentence is correct?</p>

<p>“I received candies as a Christmas present this year.”</p>

<p>Agree with JimboSteve that number is not the issue–multiple fires, collectively, constitute a boon. Neverthless, I think that there is justification for your answer, because not only . . . but also is the type of construction that calls for parallelism. So it would be better to replace “a boon” by “beneficial” or something similar, to go along with unavoidable.</p>

<p>Short version: Don’t worry about it. I think the questions on the SAT itself are better vetted.</p>

<p>“are” is used to accompany “Forest fires”. If you cut the redundant chunk between the commas, the sentence reads:</p>

<p>Forest fires are now understood not only to be unavoidable but also to be a boon to the forests.</p>

<p>Separating the sentence, you get:</p>

<p>Forest fires are now understood to be unavoidable.
Forest fires are now understood to be a boon to the forests.</p>

<p>And then you have the logic presented by JimboSteve and QuantMech.</p>

<p>I know you have an urge to fix “a boon” but the sentence is already grammatically correct. Don’t fall for the trick :).</p>