SC sound

[NarenS469]

Hi Ron,

Sorry for not being clear. I was confused with the mix of active and passive mix since a fact is being described.
After referring to the non-underlined part I see that the correct answer "its acoustic energy prevented from dissipating by....." is acting as a modifier which can be in passive mode.

Thanks for the help,

Naren

[RonPurewal]

ok.

[aflaamM589]

Hello Ron,
sound can travel through water for enormous distances, its acoustic energy prevented from dissipating by water layers of different temperature and densities

vs
its acoustic energy prevented from dissipating by water layers of different temperature and densities, sound can travel through water for enormous distances

There are sentences in GMAT official questions in which this kind of a modifier is place as initial modifier and there are questions in which it is placed at the end of a sentence after comma.

Are both same viz-a-viz meaning?
Does placement matters in this kind of a modifier?

[RonPurewal]

that wouldn't really be different, but that version would be bad writing. (that modifier is so long that most readers would have to read the sentence at least twice to understand what "its" refers to.)

[RonPurewal]

...and this is another perfect illustration of why you should NOT 'make your own versions' of GMAC's sentences.
really.
don't do it.

the GMAT only tests 1-2% of the things that can actually go wrong with english sentences (and even that may be an overestimate).
when random users try to 'edit' these sentences, the result is almost always inferior or incorrect—for reasons that the GMAT doesn't test.

making your own examples is good, but they should be...
...1/ your own examples,
...2/ SIMPLE examples, each illustrating only ONE concept (that is actually tested on this exam).

as far as the official problems are concerned, the given answer choices should be challenging enough already.
(:

[SimranjitD150]

The first clause 'sound can....distances' in this sentence is an independent clause and the second clause as per the answer choice C 'its acoustic energy...densities' is also an independent clause, so why not use a semicolon between them ?

[RonPurewal]

i'm guessing that "independent clause" just means "complete sentence"? (you should avoid using unnecessary terminology—it certainly doesn't help, and it usually just complicates the issue.)

if that's what "independent clause" means, then, no, that's incorrect. the second part is not a complete sentence.

consider:
Residents were prevented from leaving the city when the bridge broke.
this is a complete sentence.

Residents prevented from leaving the city when the bridge broke...
this is NOT a sentence (it's just "residents" + modifier).
for the same reason, the second part of choice C is not a sentence.

[RonPurewal]

why not use a semicolon between them ?

DO NOT question the correct answers!

here's a handy FAQ:

Q: Is the correct answer correct?
A: Yes.

Q: Is the correct answer wrong?
A: No.

Q: I disagree with the correct answer. Who's wrong, me or GMAC?
A: You.

Q: I wrote this other version. Is it better than the correct answer?
A: No.

[NicoleT643]

Hi Ron, I want to confirm the usage of "comma+Ved"
I used to think that comma + Ved modified the previous, however you said in the pose that comma+Ved is the same as the comma+Ving. I know how the structure "Ved, main clause" work, ie: Shaken by the earthquake, the house collapsed immediately.
However, I am not familiar with the usage of "main clause+ comma Ved", could you please give me some examples?
Also, can comma+Ved modify the noun before the comma? ( In my opinion if the usage of comma+Ving is the same as that of comma+Ved, comma+Ved does not modify the noun before comma)
Thank you.

[RonPurewal]

comma + "__ed" CAN describe just the noun that comes before it.
(= UNLIKE comma + "__ing")

comma + "__ed" CAN ALSO describe the entire agent+action that comes before it.
(= same behavior as "comma + __ing")

you should just know that both are possible.

[JbhB682]

Hi Experts - i have read the entire thread but i still have 2 questions.

In (C)

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.

(C) its acoustic energy prevented from dissipating by

In (C) - The noun boundaries is touching dissipating

In (C) - the impression is boundaries ARE RESPONSIBLE for the dissipating

How can one be so sure that boundaries IS MODIFYING "Prevented"

[StaceyKoprince]

The action being described in the sentence is not dissipating but prevented from dissipating. According to the sentence, nothing is being dissipated; rather, something is being prevented from dissipating.

Next, the thing that is doing that action (preventing the sound waves from dissipating) is the "by" noun—the boundaries.