Hi

I picked this text from Nytime.com (http://www.nytimes.com/1998/10/27/scien ... spute.html)

"Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy by boundaries in the ocean created by water layers of differing temperatures and densities."

Question 1: Does in the above question, "prevented" correctly modifies SOUND?
Question 2: Does the above question has dangling modifier error? If yes, then what could be possible construction?

Thanks in advance.

I will take a stab at this..

Question 2 - I don't think it is dangling. 'its' can have two antecedents - sound or water. But since 'its' refers to the subject, and Sound was the subject, there is no ambiguity.

Question 1 - I am not sure. It definitely does not touch 'Sound'. But there was a rule in Manhattan book that if there is a small predicate before a very long modifier, then it is acceptable that the modifier doesn't touch the noun. Now I think that in this case, the modifier - 'prevented from ... densities' definitely qualifies as a long modifier. But I am not sure whether 'can travel through water for enormous distances' qualifies as a 'small' enough predicate.
I was never sure of this rule. May be an instructor can shed some more light.

hmm.

this sentence uses a PAST PARTICIPLE (prevented...), FOLLOWING A COMMA.

this isn't an especially common construction, but i'm thinking that we can treat it in the same way that we treat the same construction with PRESENT participles (COMMA + -ING). that's one of the most common modifier constructions in written english (especially on this test), so you should know how it works.

here's how it works for comma + -ing:
(1) the modifier should modify the whole action of the preceding clause
(2) it should apply to the subject of the preceding clause

the past participle "prevented" satisfies both of these conditions in the foregoing sentence, so, IF past participles follow the same rule as do present participles - a reasonable guess (i don't know for 100% sure how the gmat treats this) - then this sentence is correct.

Ron, I'm afraid that you explanation maybe problematic. Just a couple of minutes ago, I ran into a following question in http://www.urch.com/forums/gmat-sentenc ... ances.html

Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperatures and densities.
A. prevented from dissipating its acoustic energy as a result of
B. prevented from having its acoustic energy dissipated by
C. its acoustic energy prevented from dissipating by
D. its acoustic energy prevented from being dissipated as a result of
E preventing its acoustic energy from dissipating by

It's said the OA is C. Well, even if I cannot deny Choice C, Choice A is relatively awkward by using "as a result of" rather than "by". In my hindsight, I realised it's weird to claim " sound is dissipated". Instead, it should be the energy that is dissipated.

Regarding choice E. It doesn't make any sense to say "sound prevents its acoustic energy", thus we rule out this one.

Am I right?

Are C and D not run-on sentences.

Hi Ron

This is from OG Verbal Review 2nd Edition
Question No 108

OG Answer:
C. its acoustic energy prevented from dissipating by

But it seems to be run on sentence.

Can you please clarify?

Hi, I think this is an absolute phrase; however, I understand that absolute phrases modify the result of an entire sentence. In this case I do not see how the answer C modifies the hole sentence. In addition, the OG says that E nonsensically suggests that: "sound prevents the dissipation of its own energy", but -ing modifiers can be applied to the subject or the verb. I think in this case the -ing modifier can be applied to the verb "travel", so the sound travels preventing its acoustic energy from dissipating. I think it does not sound totally nonsense. It would be nice an explanation from a MGMAT instructor. Thanks.

it is not clear to me that this problem has a legitimate enough source for us to continue the discussion any further. feel free to demonstrate otherwise if you have evidence to do so..

_________________
Tim Sanders
Manhattan GMAT Instructor