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Btw, with your experience, have you ever faced with a question that requires this "helpful..." consideration to solve? (I mean, a question that cannot be answered without considering this issue). If yes, then I am glad that you could point it out. This will help a lot. Thanks.

Nope, I've never seen a case where you absolutely have to figure out which of these "helpful..." idioms is correct. I suppose that there's no reason why they couldn't test it explicitly, but they have thousands of idioms to choose from, and I have no real reason to think that this exact issue will make or break your GMAT score. So you can eliminate this from your list of worries! :)
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I think for OA C to be correct there must be a "," between blood supply and blood. It should look as mentioned below

in eliminating from the nation's blood supply, blood that is contaminated with the virus
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sriamlan
I think for OA C to be correct there must be a "," between blood supply and blood. It should look as mentioned below

in eliminating from the nation's blood supply, blood that is contaminated with the virus

Hi, IMHO I think if a comma is inserted the way you mention, then the meaning will be changed.

A new test for AIDS has proved helpful in eliminating from the nation's blood supply, blood that is contaminated with the virus.

Separated by a comma, the word "blood" seems to modify "nation's blood supply"; it means the WHOLE nation's blood supply is contaminated with the virus. This is not intended meaning of the sentence.

Option (C): ....eliminate from B A (it could be rewritten as eliminate A from B)
A: blood that is contaminated with the virus
B: the nation's blood supply
When you put a comma in the sentence: .... eliminate from B, A....
Then it looks like A is no longer what is eliminated, but B (A=B).
Also, we will have to put a big question mark before the comma - eliminate what?

Sir GMATNinja please guide us on this concern and correct me if I'm wrong. Thank you.
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Lucy Phuong
sriamlan
I think for OA C to be correct there must be a "," between blood supply and blood. It should look as mentioned below

in eliminating from the nation's blood supply, blood that is contaminated with the virus

Hi, IMHO I think if a comma is inserted the way you mention, then the meaning will be changed.

A new test for AIDS has proved helpful in eliminating from the nation's blood supply, blood that is contaminated with the virus.

Separated by a comma, the word "blood" seems to modify "nation's blood supply"; it means the WHOLE nation's blood supply is contaminated with the virus. This is not intended meaning of the sentence.

Option (C): ....eliminate from B A (it could be rewritten as eliminate A from B)
A: blood that is contaminated with the virus
B: the nation's blood supply
When you put a comma in the sentence: .... eliminate from B, A....
Then it looks like A is no longer what is eliminated, but B (A=B).
Also, we will have to put a big question mark before the comma - eliminate what?

Sir GMATNinja please guide us on this concern and correct me if I'm wrong. Thank you.

Sorry, Lucy -- I could have sworn that I responded to this, but I think I just gave you kudos and then forgot to hit the "submit" button on my response. Bad Ninja!

I think you're spot-on here. It's really subtle, but it sounds like that extra comma would make it sounds like the whole supply is contaminated. Tricky stuff!
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GMATNinja

Could please help me with D ?? The THAT after blood refers to blood right ? So where did the virus come from ??
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GMATNinja

Could please help me with D ?? The THAT after blood refers to blood right ? So where did the virus come from ??

It might help to compare (C) and (D) right next to each other:

    (C) in eliminating from the nation's blood supply blood that is contaminated with the virus
    (D) to eliminate blood that is contaminated with the virus from the nation's blood supply

In (C), it's 100% clear that the blood is contaminated with the virus -- and that we're eliminating that contaminated blood from the nation's blood supply. That's the entire point of the sentence: the blood that's contaminated with the virus must be eliminated from the nation's blood supply.

In (D), the sentence is flipped around in ways that don't quite make sense, and aren't as clear. First, it's literally saying that the virus is from the nation's blood supply, and that's really not the point -- presumably, the virus itself came from somewhere else before it landed in the blood supply. Second, (D) literally says that we're eliminating contaminated blood in general -- not necessarily contaminated blood that is in the nation's blood supply.

It's a subtle distinction, but enough to make (C) a better answer than (D).

I hope this helps!
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Helpful to or helpful in? To use such an eternal dilemma in a GMAT question is a trap by GMAT to lure some gullible test-takers who indiscriminately choose to approve the infinitive over the prepositional phrase. So be wary; forget the dilemma and look for more concrete deal closers.

A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

(A) in eliminating blood, contaminated with the virus, from the nation's blood supply -- this choice weirdly suggests that the test helps in eliminating blood, from the nation's blood supply

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus - -- This implies that the all of nation's blood supply is contaminated.

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus---The modification is amply clear. Now the test helps to eliminate only the blood that is contaminated but not all. The correct choice by intended meaning.

D) to eliminate blood that is contaminated with the virus from the nation's blood supply -- This means that the virus comes from the nation's blood supply.

(E) to eliminate blood from the nation's blood supply that is contaminated with the virus --- Seems to say that the nation's blood supply is contaminated with the virus.

Nice practice question. Kudos to GMATPREP
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Can the relative pronoun that modify from a distance at all? I thought there were exceptions to the touch rule for some relative pronouns when say prepositions are used. If we look at B - i stupidly chose this over C because of how awkward C appeared but also I thought we needed to separate "blood" in the "blood supply blood" string in C
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dcummins
Can the relative pronoun that modify from a distance at all? I thought there were exceptions to the touch rule for some relative pronouns when say prepositions are used. If we look at B - i stupidly chose this over C because of how awkward C appeared but also I thought we needed to separate "blood" in the "blood supply blood" string in C
Yup, there are definitely exceptions to the "touch rule" for relative pronouns (i.e., modifiers beginning with "which", "that", "where", etc.) Check out this article, particularly "usage #4: "that" as a modifier (the “touch rule" and its exceptions)".

But as with many things on the GMAT, the question isn't "can this particular grammatical structure be correct?" There are painfully few absolute rules that ALWAYS apply on GMAT SC -- other than subject-verb agreement, it's hard to think of many. The more important question: "is the structure in this particular answer choice the best and clearest way to express a reasonable meaning for the sentence?"

Quote:
A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus
(C) in eliminating from the nation's blood supply blood that is contaminated with the virus
In (B), could "that is contaminated with the virus" modify "blood from the nation's blood supply"? Sure, it COULD. But it's confusing at best: since "that is contaminated with the virus" is right next to "the nation's blood supply", my first instinct is that it's saying that the whole blood supply is contaminated. That's confusing. Is the sentence definitely WRONG? Maybe not, but it's not awesome.

(C)'s only crime is that it sounds funny, and that's never a good reason to eliminate an answer choice. The meaning is much clearer than in (B): it's immediately clear that the test eliminates "blood that is contaminated with the virus."

So no, the "touch rule" isn't really an absolute rule. But there's a reason it exists (as a guideline, or whatever you want to call it): noun modifiers are usually clearer if they're as close as possible to the noun they're modifying.

I hope this helps!
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Dear Moderators,

GMATNinja generis BillyZ

I have question about choice(A).

If I change choice(A) by removing the last comma out to:
Quote:
A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus from the nation's blood supply.

COMMA + contaminated will modify preceding action clause "A new test AIDS has proved" instead of preceding noun "blood," right? That still doesn't make sense for meaning.

Thank you.
-tor
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A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

(A) in eliminating blood, contaminated with the virus, from the nation's blood supply

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus

(D) to eliminate blood that is contaminated with the virus from the nation's blood supply

(E) to eliminate blood from the nation's blood supply that is contaminated with the virus

(A) in eliminating blood, contaminated with the virus, from the nation's blood supply - Essential information between commas is incorrect.

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus - "supply" is not contaminated; "blood" is.

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus - Correct.

(D) to eliminate blood that is contaminated with the virus from the nation's blood supply - the use of "to" distorts the meaning; it gives a meaning that the very purpose of the new test was to eliminate the contaminated blood. While this may be possible, it isn't the intended meaning.

(E) to eliminate blood from the nation's blood supply that is contaminated with the virus - same error as option D and B

C is correct.
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TorGmatGod
Dear Moderators,

GMATNinja generis BillyZ

I have question about choice(A).

If I change choice(A) by removing the last comma out to:
Quote:
A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus from the nation's blood supply.

COMMA + contaminated will modify preceding action clause "A new test AIDS has proved" instead of preceding noun "blood," right? That still doesn't make sense for meaning.

Thank you.
-tor

I am not an expert, but I think "...contaminated with the virus from the nation's blood supply" gives a wrong meaning.
It seems that the blood is contaminated from the virus THAT is from the Nation's blood bank.
That is, the VIRUS is from Nation's blood bank. This is not the intended meaning.
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A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

Option Elimination - What is the difference between "help in ING" and "help to"
"Help in" is used when we want to say that the assistance contributes to achieving a specific goal. E.g., The new software will help in improving productivity. Here, "the new software" contributes to achieving a specific goal: improving productivity.

"Help to" is used when we say that the assistance enables someone to perform a specific task. E.g., The tutor helps to develop student's problem-solving skills. Here, the assistance provided by the teacher enables the students to develop problem-solving skills)

Here, are we achieving something with the new test, or the new test is enabling someone to perform the task? Here, we are achieving a goal, and what is that goal, "eliminating blood that is contaminated with the virus."

But Idiom should be the last resort to eliminate the option. And we have enough issues in the wrong answers to eliminate them even if we don't know this distinction.

(A) in eliminating blood, contaminated with the virus, from the nation's blood supply - if we remove the non-essential modifier from the sentence, it reads like "eliminating blood from the nation's blood supply." Are we trying to eliminate all the blood? Thats nonsense. Wrong.

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus - "that" modifies "blood supply." Are we saying that we are eliminating the blood supply? No. Wrong.

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus - "that" correctly modifies blood. The modifier "from the nation's blood supply" is placed correctly after elimination. Though, in general readability, this is a poor way of saying. Nonetheless, grammatically and meaning-wise, it's ok.

(D) to eliminate blood that is contaminated with the virus from the nation's blood supply - the modifier "from the nation's blood supply" modifies "the virus" as if the virus is from the blood supply. Wrong.

(E) to eliminate blood from the nation's blood supply that is contaminated with the virus - "that" referring to "blood supply" creates the wrong meaning.

We can eliminate options just because of another issue, but if we know the distinction between "help in" and "help to," it's a plus.
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Read through a number of comments here and thought I'd add my own split:

1st Filter: Idiom Help in / Aid in - this is a pretty common idiom and from what I have seen along side "Consider" one of the more frequently tested. ELIMINATE D and E

2nd Filter: A has "contaminated with the virus" as a non-essential modifier which isn't correct. It is needed to provide context to the sentence. ELIMINATE A

3rd Filter: B vs. C - in B the modifier "that is contaminated with the virus" modifies the blood supply not the blood within the blood supply. ELIMINATE B

If we slash and burn C we get the sentence:

"A new test....has proved helpful in eliminating... blood that is contaminated with the virus" KEEP C


A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus
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