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# Neuroscientists,having amassed a wealth of knowledge over

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Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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26 Jun 2010, 10:04
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Neuroscientists,having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.

A)Neuroscientists,having amassed a wealth of knowledge over the past twenty years about how the human brain and its development from birth to adulthood, are

B)Neuroscientists,having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are

C)Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are

D)Neuroscientists have amassed a wealth of knowledge over past twenty years about the brain and its development from birth to adulthood,

E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood ,

It will be helpful if experts can advise the solution and reason for the solution
[Reveal] Spoiler: OA

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Last edited by Skywalker18 on 18 Sep 2016, 11:27, edited 1 time in total.
Corrected the non-underlined part

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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09 May 2012, 05:50
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Hi All,

Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how the babies acquire language.

Error Analysis:

1) Plural subject “neuroscientists” has the plural verb “are”.
2) Modifier “having amassed…” correctly modifies the preceding noun neuroscientists. There is no construction error in the modifying phrase also. Thus, there is no error in this sentence.

POE:

Choice A: Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are : Correct. This choice is correct as is as pointed out in sentence analysis.

Choice B: Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are : Incorrect. 1) The phrase “over the past twenty years” seems to talk about the development of the brain from birth to adulthood that took twenty years to develop. However, it is the neuroscientists who took twenty years to study about the development of the brain. Thus, this choice distorts the meaning of the sentence.
2) The clause preceding conjunction “and” does not have a main verb. Thus this choice is a fragment.

Choice C: Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are: Incorrect. 1) The phrase “over the past twenty years” seems to talk about the development of the brain from birth to adulthood that took twenty years to develop. However, it is the neuroscientists who took twenty years to study about the development of the brain. Thus, this choice distorts the meaning of the sentence.
2) The clause preceding conjunction “and” does not have a main verb. Thus this choice is a fragment.

Choice D: Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood: Incorrect. In this choice, "now drawing" acts as a comma + verb-ing modifier. The focus on the main information here has shifted from " are now developing" in the original sentence to "have amassed". In the original sentence, the action that is primary is "now developing" and "amassing knowledge" comes as an additional information. This choic reverses that order by making the main action additional information and the additional information into the main action. This is a clear shift in the intended meaning.

Choice E: Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood: Incorrect. Same meaning error as in Choice D.

Hope this helps.
Thanks.
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Last edited by egmat on 15 May 2014, 06:09, edited 1 time in total.

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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06 May 2012, 10:48
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sravanth wrote:
Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.

(A) Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are
(B) Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(C) Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(D) Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood,
(E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood,

Use the flip it technique:
Having amassed.... modifies neuroscientists hence flipping it to change the construction: 'Ing(opening modifier), subject + verb,

Having [opening modifier]amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, Neuroscientists [subject] are [verb] now drawing solid conclusions about how the human brain grows and how babies acquire language. Hence option A is correct.

Try the flip it with other options and you will find that other options use incorrect construction and are hence awkward.
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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26 Jun 2010, 12:07
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Neuroscientists,having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about the human brain grows and how babies acquire language.

A)Neuroscientists,having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are

B)Neuroscientists,having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are

C)Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are

D)Neuroscientists have amassed a wealth of knowledge over past twenty years about the brain and its development from birth to adulthood,

E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood ,

It will be helpful if experts can advise the solution and reason for the solution

Im no expert but this is what I think

B. The new placement of the prepositional phrase "over the past twenty years" changes the meaning of the sentence. Instead of modifying the verb amassed it now seems to modify adulthood.

C. The way this sentence is constructed suggest a compound predicate, but the first part of the sentence has no working verb. Amassing by itself does not function as the verb of the sentence - its a modifier. If you have mahattans sc they tell you that words connected by AND should be parallel.

D. Like B. D also has a shift in meaning. By getting rid of the word ARE the phrase "now drawing solid conclusions about the human brain grows and how babies acquire language." acts more like a modifier. Put this phrase in front and you'll see the change in meaning.

E. E has the same problem as D.

The correct answer A is grammatical - there isnt anything wrong with it.
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Last edited by Detran on 26 Jun 2010, 12:27, edited 1 time in total.

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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08 Dec 2012, 12:09
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Hi htskumar,

I'll leave the boys at egmat to explain their answer further for you, but see if I can help with your second question

OG12 says, The final descriptor in present tense, now drawing conclusions...does not fit the opening clause, which is in present perfect tense (have amassed a wealth...) ----> What does this exactly mean?

This means that 'have amassed a wealth' is an event that happened in the past in an action that is completed(past perfect tense if you will), but the 'now drawing conclusions' is happening now (present tense). In interpreting the meaning of the sentence, this does not make sense.

The correct answer (A) moves from 'having amassed' to 'now drawing' this is more correct, 'having done some thing I now do something else'

Does that help?

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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25 Feb 2013, 00:24
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The construction is having done this... are now. This is more of a meaning based question.
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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30 Apr 2013, 06:51
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All duplicate threads on this topic have been merged.

Please check and follow the Guidelines for Posting in Verbal GMAT forum before posting anything in the forum.

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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30 Apr 2013, 08:04
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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22 Jun 2013, 07:32
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Neuroscientists,having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about the human brain grows and how babies acquire language.

A)Neuroscientists,having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are

B)Neuroscientists,having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are
No verb for Neuroscientists
C)Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years,and are. No verb for Neuroscientists

D)Neuroscientists have amassed a wealth of knowledge over past twenty years about the brain and its development from birth to adulthood, "drawing " is modifying what "adulthood"

E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood , "drawing " is modifying what "adulthood"

Note correct SV pair: Neuroscientists are
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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06 Sep 2013, 07:01
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Hi Mugdha,

Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.

Once again, I would say that you have done a good job in analyzing this one. However, the clause split for this one is not accurate. Let's look at the clauses in this sentence:

Cl. 1: Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about
Cl. 2: how the human brain grows and
Cl. 3: how babies acquire language.

Since we cannot have a clause without an SV pair, the additional information cannot be identified as a clause because it does not have a Subject and a Verb.

I would never advise to skip the additional information completely while doing the PoE. The best way to answer questions where answer choices confuse us is to stay focused on the meaning of the sentence. You have understood the intended meaning of this sentence alright. Now let's compare that meaning with the meaning that we get from choices D and E.

Choice D: Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, - Per this choice, now the focus (main point) of the sentence is that Neuroscientists have amassed a lot of knowledge... However, per the original sentence, the focus of the sentence is that Neuroscientists are now drawing conclusions... This choice shifts the focus of the sentence completely. The main point of the sentence in Choice A is now an additional information in this choice. On this basis, we can eliminate this answer choice.

Choice E: Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood, - Incorrect for the same reason as explained above.

So keep the intended logical meaning of the sentence as the main guide while doing the PoE.

Hope this helps.
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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15 May 2014, 03:45
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honchos wrote:
I am also your Verbal Live student.

in the above mentioned question OA is A. I did it right.

but I reasoned it on this line to eliminate D and E.

let suppose D is right for a Moment in that case Neuroscientists will have two subjects have and are so D and E cannot be correct. Is my line of thought correct?

Hi @honchos,

I'm assuming you meant that the subject 'neuroscientists' would have two verbs. However, 'are' is not present in options D and E, so the verb 'are drawing' becomes the modifier 'drawing' in these options.

Before we get to the problem in options D and E, let’s look at the intended meaning of choice A. Remember we need to first thoroughly understand the original sentence so that we can properly gauge the other answer choices.

Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.

This sentence indicates the following:
• Over the past 20 years, neuroscientists have collected a lot of knowledge about 2 things - brain and its development
• Neuroscientists are now drawing conclusions about 2 things - growth of human brain and acquiring language.
Key things to notice:

Two actions are being discussed:
a. In the past, scientists collected information
b. Now in the present context, scientists are drawing conclusions

Now let’s take a look at choice D:

Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, now drawing solid conclusions about how the human brain grows and how babies acquire language.

Let’s focus on the sequencing of tenses in this sentence. For this, I will omit “now” for now. We will bring this back after this bit of discussion.

Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, drawing solid conclusions about how the human brain grows and how babies acquire language.

Let’s read this sentence now and see what meaning it communicates.
• Over the past 20 years, neuroscientists have collected a lot of knowledge about 2 things.
• The verb-ing modifier can either present result of preceding clause or elaborate on the preceding clause. Let’s see which meaning is logical here:

o Elaborating - They collected a lot of knowledge in the past by drawing solid conclusions about 2 things.
 This seems illogical since one does not collect information by drawing conclusions.

o Result - They collected a lot of knowledge in the past and this led to them drawing solid conclusions.
 This seems rather logical. After they collected knowledge, they were able to draw solid conclusions.

But notice one very important thing. In this sentence, both the actions appear to have taken place in the past. The information was collected in the past and the conclusions were also drawn in the past.

Now bring back your understanding of choice A. Per choice A, collection took place in the past but the conclusions were being drawn in the present.

So this is the first reason for rejecting choice D - the shift in the meaning of the sentence.

Now let’s bring back the word “now”. This word interferes with the logical sequence of actions established in choice D. The logical sequence as we determined was that both actions took place in the past, but the presence of “now” forces the second action to take place in present, thereby creating a conflict.

And lastly, there is a focus shift in choice D.

Note that modifiers typically do not present the main point of the sentence: they only give additional information. In the original sentence, the subject of the main clause is “Neuroscientists” and the verb is “are drawing”. So, the intended focus is to say that neuroscientists are now drawing solid conclusions about something. This focus is now shifted to the collection of information.

So, in conclusion:

It’s very important to understand the meaning of the original sentence so that you can assess answer choices in the appropriate light. Remember, grammar is a tool to help you communicate ideas. But there is no use of learning about grammar rules if you do not pay attention to what it is that you have to communicate using these tools.

I hope this helps!

Regards,
Meghna
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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01 Oct 2014, 02:36
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TGC wrote:
Although it is already explained, I am not clear with it. And I also posted the same query before.

OE for Option (D).

The final descriptor in present tense, now
drawing conclusions ... does not fit the
opening clause, which is in present-perfect
tense {have amassed a wealth ...) and seems

Scientists have amassed a wealth of knowledge, now drawing solid conclusions.......

What is the problem with having Present perfect as main clause and a descriptor in present tense?

Second,

As in GMAT lingo, we know that -ING modifier is used for two things (1). Additional info about preceding clause (2). Result of preceding clause.

Then why OE /OG rejects option (D) saying that final descriptor seems to modify ADULTHOOD

PPS: I have read the above explanation by MEGHNA, but still there is doubt.

Hi Saurabh,
Thank you for posting your query here.

There are two problems with option D, as Meghna explained above:

1. Shift in Focus: In the original sentence the information that neuroscientists have amassed a wealth of knowledge is given in the form of a modifier. Also, it seems that the main point that the sentence wants to convey is what scientists are doing now after they have already amassed a wealth of knowledge. Now, option D shifts the focus of the sentence to the modifier part. So, this is an error.

2. Also, per the original sentence the neuroscientists have completed the action of amassing the wealth over a duration of 20 years. The verb-ing modifier "drawing" presents the result of this clause that the action of amassing the wealth of knowledge has resulted in drawing some conclusions. As we know, the verb-ing modifier takes the tense of the preceding clause in such cases. So, per this choice the conclusions are being drawn for the last 20 years. However, the presence of the word "now" interferes with the logical sequence of the actions because it indicates that the action of drawing conclusions is taking place in the present. So, there is a conflict in the meaning.

Now, the explanation provided by the OG in this case states something else. Here, the verb-ing modifier "drawing" modifies the preceding clause, not the preceding noun "adulthood".

Hope this helps!
Regards,
Deepak
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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26 Jun 2010, 18:52
Detran, Gurpreet , thanks a ton . +1 kudos to both of you .
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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15 May 2012, 04:41
Hi e-GMAT,

Option D - Error Analysis

Quote:
the modifier “now drawing” seems to modify “adulthood” which makes no sense

Since this is an ING modifier followed by comma, should it not modify the preceding clause and not the noun?

OG12 says, The final descriptor in present tense, now drawing conclusions...does not fit the opening clause, which is in present perfect tense (have amassed a wealth...) ----> What does this exactly mean?

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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08 Dec 2012, 05:01
on SC, we normally face least 2 answer choices which are grammatical but have meaning problem and the focus on meaning helps us a lot.

D and E contain typical meaning error on gmat sc- the relation between 2 verbs/actions is distorted . This error appears offten on the all -is -underlinded question, a very hard one. be ready for this kind of error.

the time order of 2 actions verbs/action can be distorted ( as in this cases)

the meaning realation of 2 actions/verbs can be distorted. modifier relation is changed in to dependent relation or vice versa. "do and do" is changed into "do +comma+doing"
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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10 Jan 2013, 07:45
in D and E,
comma+drawing
modifies the preceding clause. T

this is grammatical

but

comma+doing modifying preceding clause say about effect of or how the preceding clause happen. This meaning has no sense in here . D and E are wrong
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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30 Apr 2013, 08:23
daagh wrote:
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From the way it is going on, I think we are going to need more merger specialists like you

Thank you, daagh, for your support.

I personally feel that it is very uncomfortable for anybody to go through some 15 or 20 topics on the same question to get answer to his/her doubt/question. I am trying my best to help the community by streamlining the questions.

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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19 Jun 2013, 19:47
egmat wrote:
Hi All,

Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how the babies acquire language.

Error Analysis:

1) Plural subject “neuroscientists” has the plural verb “are”.
2) Modifier “having amassed…” correctly modifies the preceding noun neuroscientists. There is no construction error in the modifying phrase also. Thus, there is no error in this sentence.

POE:

Choice A: Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are : Correct. This choice is correct as is as pointed out in sentence analysis.

Choice B: Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are : Incorrect. 1) The phrase “over the past twenty years” seems to talk about the development of the brain from birth to adulthood that took twenty years to develop. However, it is the neuroscientists who took twenty years to study about the development of the brain. Thus, this choice distorts the meaning of the sentence.
2) The clause preceding conjunction “and” does not have a main verb. Thus this choice is a fragment.

Choice C: Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are: Incorrect. 1) The phrase “over the past twenty years” seems to talk about the development of the brain from birth to adulthood that took twenty years to develop. However, it is the neuroscientists who took twenty years to study about the development of the brain. Thus, this choice distorts the meaning of the sentence.
2) The clause preceding conjunction “and” does not have a main verb. Thus this choice is a fragment.

Choice D: Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood: Incorrect. 1) In this choice, the second clause preceded by comma does not have a main verb making it a fragment.
2) Generally, a clause is introduced after the comma. But here, there is neither any subject nor any verb for the clause. Moreover, the clause is a fragment.
3) Also, the modifier “now drawing” seems to modify “adulthood” which makes no sense.

Choice E: Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood: Incorrect. 1) In this choice, just like choice D, the second clause preceded by comma does not have a main verb making it a fragment.
2) Generally, a clause is introduced after the comma. But here, there is neither any subject nor any verb for the clause. Moreover, the clause is a fragment.
3) Also, the modifier “now drawing” seems to modify “adulthood” which makes no sense.

Hope this helps.
Thanks.

I am getting confused with this statement in B and C
"The clause preceding conjunction “and” does not have a main verb. Thus this choice is a fragment"
Can somebody please explain me clearly what is the clause here and which and we are talking.

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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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21 Aug 2013, 21:08
regarding D and E

doing phrase here as participle phrase modifies the previous clause/main clause. there must be meaning relation between the two actions , one by doing and one by main verb. they are not independent action.

D and E satify this meaning relation.

the main problem with D and E is "now"

doing take the tense of main clause, "have massed" but "have massed" can not go with "now' . NOT LOGIC.
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Re: Neuroscientists,having amassed a wealth of knowledge over [#permalink]

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23 Aug 2013, 00:50
plumber250 wrote:
Hi htskumar,

I'll leave the boys at egmat to explain their answer further for you, but see if I can help with your second question

OG12 says, The final descriptor in present tense, now drawing conclusions...does not fit the opening clause, which is in present perfect tense (have amassed a wealth...) ----> What does this exactly mean?

This means that 'have amassed a wealth' is an event that happened in the past in an action that is completed(past perfect tense if you will), but the 'now drawing conclusions' is happening now (present tense). In interpreting the meaning of the sentence, this does not make sense.

The correct answer (A) moves from 'having amassed' to 'now drawing' this is more correct, 'having done some thing I now do something else'

Does that help?

James

Somehow unclear as to why OG explained the Option D as incorrect

"The final descriptor in present tense, now
drawing conclusions … does not fit the
opening clause, which is in present-perfect
tense (have amassed a wealth …) and seems

What is the issue with this as per meaning.

Over the past 20 years Neuroscientists have amassed.... Blah Blah, Now drawing ........Blah Blah

Time sequence :

In the time of 20 years they have amassed a wealth of knowledge,(Effect of the amassing of knowledge and thereby what they are doing now)Now drawing ........Blah Blah......

Rgds,
TGC !
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Re: Neuroscientists,having amassed a wealth of knowledge over   [#permalink] 23 Aug 2013, 00:50

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