Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless wings, shaped so smoothly and perfectly that the air passing over them would not become turbulent.
(A) wings, shaped so smoothly and perfectly
(B) wings, wings so smooth and so perfectly shaped
(C) wings that are shaped so smooth and perfect
(D) wings, shaped in such a smooth and perfect manner
(E) wings, wings having been shaped smoothly and perfectly so

Please explain.

Regards,
Brajesh

Agree with B.

Wings are smooth and they are shaped perfect. They are not shaped smooth. You don't shape a thing to be smooth.

Only C caters to clarity ( we know who is shaped smoothly) with no
repetition (...wings,wings...). The repetition sounds poetic though

Dahiya, could you pls elaborate on this rule? I have not seen this before. How about a modifying sentences?
Using the latest techniques, Dahiya solved the problem.
The first clause does not have a subject.

Second part is a dependent clause with no subject. A and D out.

One more point to be noted is "smooth" and "perfect" are adjectives and should modify nouns (wings) not the verbs (shaped). C is out.

"Smoothly" and "perfectly" are adverbs and should modify verbs (shaped) not nouns (wings). B in.

E is awkward.[/quote]

Dahiya, could you pls elaborate on this rule? I have not seen this before. How about a modifying sentences?
Using the latest techniques, Dahiya solved the problem.
The first clause does not have a subject.[/quote]

Part1:
Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless wings.

Part2:
shaped so smoothly and perfectly that the air passing over them would not become turbulent.

Part2 don't have a subject. Yes I agree modifiers may not have subjects. But this modifier may either refer to "airplanes with frictionless wings" or to "frictionless wings". So it will be better to make it an independent clause by inserting a subejct.

Hope this helps.[/quote]

Isn't it necessary for an independent clause to have a semicolon before it?

Dahiya Boss - ONCE AGAIN HATS OFF!!!! What an explanation - I was reading it and going WOW!!

By the way, for the grammatically inclined - the choice B is an example of something called a Resumptive Modifier.

Resumptive Modifiers aid in varying sentence style; I don't think GMAT really tests sentence variety; however, as in this example, it has employed Variety in the correct choice.

One may ask how are we to identify whether the second part SHOULD rather be an independent clause than a phrase? Not so sure; I for example picked up B partly because I knew about resumptive modifiers and partly because I could spot the errors in the other choices easily.

But eventually it's the good old POE that comes to our rescue.

As Dahiya has pointed out that the original sentence is (or actually SHOULD be) a combination of two independent clauses with the subject of the second clause missing --- i guess it takes a fair bit of practice(especially in timed exam conditions) to recognize the various Parts in a sentence and convoluted ones such as this example are even harder to parse - one could very well think that "shaped so smoothly and perfectly..." simply modifies Wings (as mailtheguru points out) - Here I want to say one thing -

Consider the revised sentence below -

Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless wings shaped so smoothly and perfectly that the air passing over them would not become turbulent.

Can you spot the difference between the above sentence and the original sentence? I have just removed the COMMA after wings to make "shaped so smoothly and perfectly that the air ...become turbulent" a PHRASE that modifies wings. But because A COMMA had been inserted in the original sentence, the whole meaning of the second part changed completely.

Dahiya - Would appreciate your comments on the above..

I am posting the link on resumptive modifiers.. this site in general is quite helpful to build grammar insights.

http://grammar.ccc.commnet.edu/grammar/sentences.htm

Wings has to be restated for clarification. "having been" in E is awkward.

Bagging (B) here for brevity.

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