Seems like there are some questions about the grammar here, so I thought I'd weigh in. This first one is tough, and I can't even say I'm 100% sure, but I'll give my reasoning and hope for the best! For a bit more info on this idiom, consider this comment thread: http://www.manhattangmat.com/forums/man ... t2566.html
214. Climatic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the weather.
(A) so gradual as to be indistinguishable
ANSWER: This uses the idiom correctly. "So gradual as to be indistinguishable" is correct. We can say "His work is so famous as to be a cliché."
(B) so gradual they can be indistinguishable
PROBLEM: We need something after "gradual" to segue here. For example "that" or "as".
(C) so gradual that they are unable to be distinguished
PROBLEM: No reason to use the passive voice on "distinguished", because we don't know who is doing the distingushing. Also, "they are unable" makes it sound like they're TRYING to be distinguished, and can't do it.
(D) gradual enough not to be distinguishable
PROBLEM: There's no reason to use "enough" here. It marks a subtle shift in meaning. We want to emphasize that shikts are so gradual that we can't tell the difference between them and ordinary fluctuations. This version, with "enough", makes it sound very direct, as if there's some level of "gradual-ness" that makes shifts indistinguishable from ordinary fluctuations. Finally, putting the not in there instead of the word "indistinguishable" confuses things. It would be weird to say "I am tired enough not to be able to stay awake on my feet" as opposied to "I am tired enough to fall asleep on my feet".
(E) gradual enough so that one cannot distinguish them
PROBLEM: Even worse than above. We still have enough, but we've also added an unnecessary pronoun ("one")
OKAY! One down...
BTW, this next one presents a different version of "so as to", for what it's worth. This one just means "in order to", which is different from the one above.
219. Congress is debating a bill requiring certain employers provide workers with unpaid leave so as to care for sick or newborn children.
(A) provide workers with unpaid leave so as to
PROBLEM: Two issues. We need the idiom "requiring X to Y". This misses the "to". Also, "so as to care" makes it sound as if Congress is doing the caring.
(B) to provide workers with unpaid leave so as to
PROBLEM: This addresses the first issue mentioned above, but not the second.
(C) provide workers with unpaid leave in order that they
PROBLEM: This lacks the "to". Also, the idiom is "in order to", not "in order that".
(D) to provide workers with unpaid leave so that they can
ANSWER: This has the "to", and correctly places the pronoun "they", so that we know it's the workers who will be caring for their children.
(E) provide workers with unpaid leave and
PROBLEM: Lacks the "to", and also sounds like Congress is doing the caring.
Hope that helps! (Also, in the future, please underline the section of the sentence at issue. It makes it easier to see where the answer choices go.)
Tommy Wallach | Manhattan GMAT Instructor | San Francisco
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