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AbdurRakib wrote:
The Official Guide for GMAT Review 2018Practice QuestionSentence Correction
Question No.: 699
Researchers now regard interferon
as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.
A. as not a single substance, but it is rather a biological family of complex molecules that play
B. as not a single substance but as a biological family of complex molecules playing
C. not as a single substance but as a biological family of complex molecules that play
D. not to be a single substance but rather a biological family of complex molecules playing
E. not as a single substance but instead as being a biological family of complex molecules that play
Concepts tested here: Modifiers + Parallelism + Verb Forms + Idioms + Awkwardness/Redundancy• “not A but B” is a correct idiomatic usage; A and B must be parallel and comparable.
• The word "considered" does not require a conjunction or a helping word/phrase; “consider/considered” is always followed directly by the noun, and the similar word "regarded" must be followed by the conjunction "as"; correct usages: Jack is “considered a math genius” or Jack is “regarded as a math genius”.
• “being”, rendering it awkward and needlessly wordy; remember, “being” is only to be used when it is part of a noun phrase or represents the passive continuous verb tense; the use of passive continuous must be justified in the context.
• Information that is permanent in nature is best conveyed through the simple present tense.
A: This answer choice fails to maintain parallelism between A (“as not a single substance”) and B (“it is rather a biological family of complex molecules”) in the idiomatic construction “not A but B”; remember, “not A but B” is a correct idiomatic usage; A and B must be parallel and comparable. Further, Option A uses the redundant phrase “but it is rather”, rendering it awkward and needlessly wordy.
B: This answer choice incorrectly uses the present participle (“verb+ing” – “playing” in this case) to refer to information that is permanent in nature; remember, information that is permanent in nature is best conveyed through the simple present tense.
C: Correct. This answer choice correctly maintains parallelism between A (“as a single substance”) and B (“as a biological family of complex molecules”) in the idiomatic construction “not A but B”. Further, Option C correctly uses the simple present tense verb “play” to refer to information that is permanent in nature. Additionally, Option C correctly uses the idiomatic construction “regard as”. Besides, Option C is free of awkwardness or redundancy.
D: This answer choice fails to maintain parallelism between A (“to be a single substance”) and B (“a biological family of complex molecules”) in the idiomatic construction “not A but B”; remember, “not A but B” is a correct idiomatic usage; A and B must be parallel and comparable. Further, Option D incorrectly uses the present participle (“verb+ing” – “playing” in this case) to refer to information that is permanent in nature; remember, information that is permanent in nature is best conveyed through the simple present tense. Additionally, Option D incorrectly uses the unidiomatic construction “regard to be”; remember, "regard" must be followed by the conjunction "as". Besides, Option D redundantly uses “but” alongside “rather”, leading to awkwardness and redundancy.
E: This answer choice incorrectly uses the word “being”, rendering it awkward and needlessly wordy; remember, “being” is only to be used when it is part of a noun phrase or represents the passive continuous verb tense; the use of passive continuous must be justified in the context. Moreover, Option E redundantly uses “but” alongside “instead”, leading to further awkwardness and redundancy.
Hence, C is the best answer choice.To understand the use of "Being" on GMAT, you may want to watch the following video (~2 minutes):
To understand the concept of "Simple Tenses" on GMAT, you may want to watch the following video (~2 minutes):
To understand the use of "Considered" and "Regarded" on GMAT, you may want to watch the following video (~1 minute):
All the best!
Experts' Global Team