<p>These novels move willing readers away from their humdrum lives **and into a world that is **at once **fanatastic and mysterious. **No error</p>

<p>E, no error.</p>

<p>Oh wait, it could be B - that might be an ambiguous pronoun. Do you have the answer?</p>

<p>I think that one would be kind of stupid to think the pronoun refers to "novels" but you might be correct there. Hard to tell, it's not exactly ambiguous if it's that clear is it?
Is "at once" correct? I think it is, but I'm not sure. Shouldn't it be more like "world that is at once both fantastic and mysterious"?
Anyone care to help here?</p>

<p>Haha yeah, I don't think anyone would actually assign "their" to "novels." But I'm not sure.</p>

<p>Hmm, that's a good point. I'm not sure whether "at once both" is a set phrase (in the same way neither...nor and as...as are set correlative conjunctions), but that is the way I most commonly see it used. You're probably right about D.</p>

<p>The correct answer is E. I thought that the D would be correct because the sentence was supposed to be "at once both" not "at once."</p>

<p>^ Not sure what you mean...did the original question say "at once both," and you accidentally left the "both" out?</p>

<p>The original sentence is:These novels move willing eaders away from their humdrum lives and into a world that is at once fantastic and mysterious. No error</p>

<p>I thought that both needed to be inserted after "at once" because i thought both...and was appropriate for this sentence, but this is not the case. There is no error in the sentence</p>

<p>Oh, OK. Yeah, since "at once" is used to mean "simultaneously," the "both" is unnecessary. That usage appears frequently, but it's redundant when you think about it.</p>