Since the 1930s aircraft manufacturers have tried to build airplanes

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of the crucial part of this sentence is that “wings” (and not “airplanes”) were smooth and perfectly shaped; hence, “so smooth and perfectly shaped that the air passing over them would not become turbulent” must clearly modify “airplanes”; only choices B and E do that.

Concepts tested here: Meaning + Modifiers + Tenses

• "so cause that effect" is the correct, idiomatic usage.
• In a “noun + comma + phrase” construction, the phrase must correctly modify the noun; this is one of the most frequently tested concepts on GMAT sentence correction.
• An adjective can only modify a noun; it cannot modify another adjective; to modify an adjective, an adverb must be used; generally, adjective+ly leads to an adverb.

A: Trap. This answer choice incorrectly uses the phrase “shaped so smoothly and perfectly” to modify the noun “airplanes” rather than the noun “wings”, altering the sentence to incorrectly imply that the airplanes are shaped in a smooth and perfect manner; the intended meaning is that the wings are smooth and perfectly shaped; remember, in a “noun + comma + phrase” construction, the phrase must correctly modify the noun.

B: Correct. This answer choice uses the phrase “wings so smooth and so perfectly shaped” to modify the noun “wings”, preserving the intended meaning of the sentence- that the wings are smooth and perfectly shaped. Further, Option B correctly modifies the noun "wings" with the adjectives "smooth" and "perfectly shaped". Additionally, Option B correctly uses the idiomatic construction "so cause that effect". Besides, Option B is free of any awkwardness or redundancy.

C: Trap. This answer incorrectly uses the adjectives “smooth” and “perfect” rather than their adverb forms to modify the verb "shaped”; please remember, an adjective can only modify a noun; generally, adjective+ly leads to an adverb.

D: Trap. This answer choice incorrectly uses the phrase “shaped in such a smooth and perfect manner” to modify the noun “airplanes” rather than the noun “wings”, altering the sentence to incorrectly imply that the airplanes are shaped in a smooth and perfect manner; the intended meaning is that the wings are smooth and perfectly shaped; remember, in a “noun + comma + phrase” construction, the phrase must correctly modify the noun.

E: This answer incorrectly uses the unidiomatic construction "cause so that effect”; please remember, "so cause that effect" is the correct, idiomatic usage. Further, Option E incorrectly uses the needlessly wordy phrase “having been shaped”, leading to awkwardness and redundancy.

Hence, B is the best answer choice.

To understand the concept of "Phrase Comma Subject" and "Subject Comma Phrase" on GMAT, you may want to watch the following video (~1minute):



All the best!
Experts' Global Team

Official Explanation

Diction; Logical predication

The sentence as written is not stated clearly. For example, it is unclear what is shaped so smoothly and perfectly; it could be either the airplanes or the wings. Upon considering the likely intended meaning, along with a review of the other answer choices, it seems most likely that the phrase is intended to modify frictionless wings.

Next, we need to consider whether it makes more sense to say that the wings are smooth or shaped smoothly. This issue can be determined only by considering the most plausible intended meaning rather than by considering just the grammar of the sentence. The idea of being smoothly shaped would seem already to be part of the idea of being shaped perfectly, and therefore it is redundant. On the other hand, having a surface that is very smooth would be crucial in a quest to make an airplane wing frictionless; for this reason, it makes sense to point out that the wings themselves are smooth.

A. This choice is incorrect for the reasons stated above.

B. Correct. Given the repetition of the word wings, it is clear that what follows modifies wings and not airplanes. Describing the wings as smooth and perfectly shaped clearly conveys what is most likely intended.

C. In this version, note that shaped is modified. For this reason, proper grammar requires that the adverbs smoothly and perfectly are needed rather than the adjectives smooth and perfect. However, as discussed previously, the intended meaning of the sentence would be better conveyed if we used the adjective smooth to modify wings rather than the adverb smoothly to modify shaped.

D. It is initially unclear what is being described as having been shaped in such a smooth and perfect manner; it could be either the airplane or its wings. Even if that were clarified, however, the sentence would be flawed: the sentence is intended to describe the wings themselves, not the manner in which the wings were shaped. That is, this wording could be interpreted as referring to the nature of the wings themselves or to the process through which they were made. This ambiguity makes the meaning of the sentence unclear.

E. This version is very awkwardly worded, mainly because of having been. Furthermore, this version describes the act of shaping the wings. Because the sentence is instead meant to describe the wings themselves, this choice is incorrect.

The correct answer is B.

A) "shaped so smoothly..." is a dependent clause with no subject
B) correctly introduces the dependent clause with the subject "wings"
C) "smooth and perfect" are adjectives. We need adverbs "smoothly and perfectly" in order to modify verb "shaped"
D) again, the dependent clause is introduced with no subject or pronoun (ie which or that) which refers to the subject of the independent clause
E) to convey the idea of magnitude, "so" should have been placed before the adverbs which intend to modify the verb "shaped". Also, use of present perfect is unappropriate

Dharmin,Anand

you are correct. but lets set a trend ourselves. When i was taking my GMAT, i used to attempt to explain most ,if not all, of my answers, right or wrong. let us try to promote this culture. Anand does a great job, but we want others to explain their answers too.

Here the absolute phrase starting with "shaped" needs to clearly identify what is shaped...wings are shaped OR airplanes are shaped.

Only B and E fit that criteria. It wouldnt be hard to eliminate E.

B is so much better and concise.

regards
Praet

I looked into this one again and I believe the reason why A is not as good as B is simply because the relative pronoun "them" at the end of the sentence does not have any clear referrent. Does it refer to "airplanes" or "wings"? The same goes for A's participial phrase form which could refer to either one of those 2 preceding nouns.

For example, you have these 2 participial phrase structures:
eg The airplane kit model in the closet, built with such perfection that it amazed the whole family, was part of his collection.

As you can see above, there is an ambiguity as to what was built with such perfection. Is it the subject of the prepositional phrase in red or is it the "airplane kit model"? Because of this ambiguity, relative pronoun "it" also have an ambiguous referrent. If the author meant that it was the closet which was built with..., then he should repeat the word closet to clear such ambiguity. By the same token, "it" should then have a clear referrent.

eg The airplane kit model in the closet, a closet built with such perfection that it amazed the whole family, was part of his collection.

You can apply this same concept to the original question

I got my answer.
Such a silly question .

In (B), "smooth" and "shaped" (adjectives) are modifying Noun (wings). So it is right.
In (C), "smooth" and "perfect" (adjectives) are modifying Verb (shaped) but we know that only Adverbs can modify Verb. So it is wrong.

This is a complex question which has been discussed earlier also. You can search it on the forum.

The answer is B.

We need to repeat the word WINGS to clarify that it was the wings that the manufacturers were trying to smoothen and give a perfect shape to.

In A, shaped so smoothly and perfectly ends up modifying Aircraft manufacturers creating an absurd meaning.

In C, we need SMOOTHLY and PERFECTLY (Adverbs) rather than SMOOTH and PERFECT (adjectives) to modify the verb SHAPED

D has a problem similar to A

E repeats the word WINGS but is idiomatically wrong - the correct idiom is SO X THAT Y

Got it wrong in first go!

only B & C are compelling options!
this question is checking concept of "resumptive modifiers", which demands repartition of word "wings"
Also, option C could have been right provided we had perfectly; only adverbs can modify verb (verb = shaped). perfect is adjective. Further, "shaped smoothly" would have been wrong. you can shape perfectly, but not smoothly. In B this is corrected; wings so smooth (adjective) and perfectly (adverb) shaped
. . so answer is B


Now, What are RESUMPTIVE MODIFIERS;read below

By adding modifying phrases to the end of a sentence, a writer can take the reader in new, sometimes unexpected directions. A resumptive modifier picks up a word or phrase from a sentence that seems to be finished and then adds information and takes the reader into new territory of thought. Because resumptive modifiers are, by nature, repetitive, they tend also to add a sense of rhythm to a sentence.

Example: The Swiss watchmakers' failure to capitalize on the invention of the digital timepiece was both astonishing and alarming — astonishing in that the Swiss had, since the beginnings of the industrial revolution in Europe, been among the first to capitalize on technical innovations, alarming in that a tremendous industrial potential had been lost to their chief competitors, the watchmakers of Japan.

for TWO MORE EXAMPLES of this type of question, search following questions in forum
"Yellow jackets number among the 900 or so species . . . "
"In a crowded, acquisitive world, the disapperance of lifestyles such as those once . . ."

Target760

Why is "C" an easy elimination. I did not understand

Hi rrkan, tricky question, duped me too.

C is out cos - shaped so smooth and perfect (here smooth and perfect are supposed to modify shaped - ed verb - thus we need adverb and an adjective, but if you see we have both as adjectives)

Choice B it is, since "...so smooth....so perfectly shaped" i notice how adverb perfectly is modifying shaped and adjective smooth is modifying adverb perfectly and also parallelism of so x so y is maintained
Hope this helps

Not sure why A is wrong. Unless comma has a different meaning..

Per my analysis shaped is a verb playing the modifier role and -ed modifier always modifies the closest noun - which is wings.

Smoothly and Perfectly are adverbs intended for shaped and also the idiom so and that are considered.

Any help from experts?

A is wrong because there is a dangling modifier which does not clearly state whether the aircraft is smooth and perfectly shaped or the wings.

if you want to modify the noun 'wings' , you will need to place a 'which' (non essential modifiers) after the comma.

hi lostthepie,
Can you please explain why ed modifer can't modify the near by noun wings and only which can perform that?

My 2 cents....

verb ed can modify nouns for sure. but if you notice carefully, here noun is "airplanes" "with....wings" is a prepositional phrase modifying "airplanes". Thus it creates an ambiguity as to what exactly verb ed is modifying

use of "that" will make the modifier an essential one, thus it will carefully modify the entire noun phrase "airplane .... wings" and not just airplanes or wings

hope this helps

So use of that and which is correct if we want to modify a noun with prepostional phrases and ver-ed modifier doesnt have this flexiblity ?am i right?

That is correct.

Follow the links below, very helpful in clearing the doubts in discussion here. It is better to understand the concept clearly than simply remember grammar rules

usage-of-that-doubt-150338.html

noun-modifiers-can-modify-slightly-far-away-noun-135868.html

verb-ed-modifiers-vs-verb-ing-modifiers-125611.html

Hope I was of help

Cheers

+1 kudos mate for sharing the link.

But if you see those posts we see that verb-ed modifier is also a noun modifier for sure.SO all noun modifiers can modify the far away noun.So verb-ed modifiers can also modify far away noun i guess..please correct me if am wrong