You're right to think about the meaning, and the meaning is that the cannon (generally) shoots dead chickens at planes, and not that it is (currently) shooting dead chickens at planes. I'm also going to avoid any questions on cannons and chickens by switching to a different example

(1) People who eat lots of vegetables will live longer than...

(2) People eating lots of vegetables will live longer than...

The second one seems to be talking about people who are (right now) eating lots of vegetables (people who are eating lots of vegetables...). But that's not the meaning that we want. We want to talk about people who (generally) eat lots of vegetables, and (1) does a better job of communicating that meaning.

Also, helpful to demonstrate is unidiomatic in option A.
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Tense + Logic

A can be eliminated due to use of “to demonstrate” rather than “in demonstrating”.
The correct idiom is:
Helpful in demonstrating
Help to demonstrate

B is wordy in “as a demonstration of”

C and D can be eliminated because of the use of ‘proves’. (There’s no universal law being talked about here)

E is the best choice.

generis AjiteshArun GMATNinja VeritasKarishma

I managed to narrow it down to A and E and ultimately went to pick E since
noun form sounded better than the usage of an infinitive as in A.

I rejected B,C and D on account of incorrect usage of itself which according to me
refers to some sort of action, which does not make sense in the context of the sentence.
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When i Speak in English, and it happens very rarely, i use "helpful" with preposition "for" " i.e. helpful for something


helpful to do something - is not idiomatic expression, i never heard that combination. if it were "helps to demonstrate" that would be fine


Since i excluded "help to demonstrate' hence i will exclude A and D.


Now left with B, C, E

in B "itself" is rebundunt "the gun didnt prove itself"

in C same issue

In E - everything looks fine to me.

so i will choose E

Method applied in solving SC is POE (PREDICT: OBSERVE: ELIMINATE) WAY OF SAMURAI

adkikani , look very carefully at the modifiers of the subject of the sentence.

This official sentence is strange.
Its strange quality deepens when the modifiers are understood.

adkikani , one further hint: isolate the modifiers of the subject and the subject.

Of the two options with modified subjects, which modified subject is clearer?

Frequently, we can condense relative clauses (such as a THAT clause) to participles or participial phrases (such as a verbING word or phrase),
but at times meaning is clearer when we do not condense.
If the participle has multiple meanings that create ambiguity, even if that ambiguity is cleared up by the rest of the sentence, choose the
construction that has no ambiguity.

Noam Chomsky, a famed linguist, captured the essence of the issue with this truly ambiguous example:
Flying planes can be dangerous.
Are the objects moving around in the sky dangerous? [flying planes = planes that are flying]
OR
Is being a pilot dangerous? [Pilots are the people who are flying planes.]

In this question, the modifier in the incorrect answer arguably is neither misplaced nor technically ambiguous.
But its potential to confuse should make the correct choice easier.

Hope that helps.
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to me its hilarious with or without modifiers because when i read "shooting dead chickens" i understand that chickens were already dead but they were still being shot by gun

Between A & E, A looks like the better option because of the difference in meaning.

IMO, a cannon *that shoots* ... in E sounds like the cannon proved helpful in demonstrating the results of a jet flying into a flock of birds.
Whereas, as per the meaning, it should be the entire process of shooting dead chickens to demonstrate the impact, as presented in A.

Needs experts view here daagh AjiteshArun .

generis

Please accept my humble apology for not comprehending your hint.







In both A and E:
Opening modifier: According to United States Air Force officials
correctly modifies the noun: a cannon

In A, a verb-ing modifier without coma i.e. shooting (note that shooting is placed next to cannon) will correctly modify only preceding noun: cannon.
There is no question of coma+verb-ing (causal/ how aspect of preceding clause here)
This is a classic case of verb-ing acting as an adjective.
What type of cannon: the one that shoots dead chickens.

This is similar to your example:
Flying planes can be dangerous.
What types of planes: Flying.
Noun: planes
Verb: can be

In E, the noun modifier that correctly refers back to a cannon
Since cannon is singular and the verb for that (shoots) is correct, I see no ambiguity here too.

Let me know your two cents.
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10 seconds answer :

"helpful in " is the idiom preferred by GMAT ... this is supported by GMATNinja
as soon as i see "helpful" i look for "in" ...that's it .. if more than 1 ans choice has "helpful in" then look for other error

That'll get you the answer. In this case. However, it is easy to make sentences in which helpful is followed by something other than in, and the sentence is still correct. Context is important.

It'll be helpful for us to know the meaning behind her words.
That explanation was helpful to us.
You were very helpful.

Look for the in only if there is something that the helpful bit "provided".
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Pardon me for being vague..
I should have added that "helpful in" is preferred when a purpose verb ( supposedly defining the purpose) .

Thank you for pointing this out...
Would have misguided fellow students.

Posted from my mobile device

Not every cannon but a particular cannon that shoots chicken so "that" is required
Narrow down to D and E

itself in D change the meaning of sentence
So E Is correct answer

adkikani , I am about to post the official answer, and I can't quite tell whether
anyone has picked up on the full extent of the ambiguity.

I think not.

Is shooting an adjective or a gerund?
More on that in the OE.

Yes, in context,
The "cannon shooting = the cannon that shoots projectiles."
And yes, correct, in that case, "shooting" is an adjective.

Nice work.
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OFFICIAL ANSWER

• Option A is incorrect because a cannon shooting imprecisely
suggests either an event, the shooting of dead chickens at airplanes, or
what appears to be intended, [that is,] a description of
the cannon that specifies its use.

• Choices B and C also include this error.

• In addition, choices A, C, and D use unidiomatic constructions, to demonstrate and as demonstrating,
after helpful, rather than the correct in demonstrating.

• The phrase as a demonstration of in choice B is idiomatic but
inappropriate because it suggests a single event rather than a
purpose.

• Choices B, C, and D all introduce an unnecessary itself as well, and

• C and D wrongly use the present tense proves rather than has proved to indicate recently completed
action.

• The best answer is choice E.



AdityaHongunti , for a good restult and for graciousness. Let's hope that your courtesy and graciousness spread.

dave13, for a good answer and consistently a good sense of humor

adkikani, a good answer, persisitence and curiosity


Finally, rever08 and
shibanis01 = good answers

Happy kudos, All!
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Isnt't to+verb used for stating an intention or purpose? I am confused when to use to verb and when to use +ing.

Why should A) be incorrect then? It gives a description of the canon, I mean that's what modifiers do.
I also don't get why the most upvoted answer states that "shooting" is a progressive, I've rarely seen a progressive -ING form on the GMAT and if so, it ususally was preceded by a helping verb "Jane IS swimming"
Totally confused why we now interfer from a modifier that it might imply the action of CURRENTLY doing something.

Could you shed light on my doubts please?
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Hi AndrewN

I'm little confused the usage of present tense in E, I cant understand whether there is any recently completed action ? appreciate your help!
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Hello, Hero1kF. How about we break down the sentence in question, with an eye on the verbs?

According to United States Air Force officials, a cannon that shoots dead chickens at airplanes has proved helpful in demonstrating what kind of damage can result when jets fly into a flock of large birds.

Shoots is the action of the cannon, and the embedded clause that shoots dead chickens is used to modify the cannon, to describe what type of cannon was used in this study (or at least what type of ammo was used). This action may or may not have occurred in the recent past, not much different from saying that Leonardo da Vinci remarked on the way light refracts to give the sky its blue coloration.

Has proved indicates that the finding remains valid, but also that the experiment may be ongoing. A conjugation into the simple past, without has, could work as well, but now the experiment would seem concluded, the results definitive.

Can result shows a hypothetical outcome. Again, the simple past, results, would be more definitive.

Fly illustrates the action of a jet, whether that jet will be flown today, tomorrow, or at some point in the distant future.

I hope that helps answer your question. If something else remains unclear, feel free to bring it to my attention. Thank you for tagging me.

- Andrew

Thanks AndrewN


According to United States Air Force officials, a cannon that shoots dead chickens at airplanes has proved helpful in demonstrating what kind of damage can result when jets fly into a flock of large birds.

(E) that shoots dead chickens at airplanes has proved helpful in demonstrating

Few more questions, as I am not very grammar savy and don't have lot of knowledge about grammar, especially verbs. I would like to ask few questions

has proved is a present perfect tense ?

also, if you had to elminate D What would be your reasoning



D doesnt sound ok to my ears, but I cant say for sure whats wrong in D

Also, fun fact, when you didn't have your own picture as profile Pic, your formal and polite tone in forums gave me an impression that you were an old gentlemen in his 40's.
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