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Geologiests in South Africa

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Geologiests in South Africa

by GmatGreen » Tue Feb 18, 2014 9:44 am
Geologists have found that streams in the Karoo basin of South Africa changed suddenly at the end of the Permian period 250 million years ago, from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas without deep-rooted vegetation to hold the soil together.

(A) from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas without deep-rooted vegetation to hold

(B) from the meandering shape typically found in well-vegetated zones to the braided pattern that they find in areas without deep-rooted vegetation for holding

(C) from the meandering shape typical in well-vegetated zones to the braided pattern found in areas where it is without deep-rooted vegetation for holding

(D) shifting from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas where it is without deep-rooted vegetation for holding

(E) shifting from the meandering shape that is typical in well-vegetated zones to the braided pattern being found in areas without deep-rooted vegetation to hold
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by Patrick_GMATFix » Tue Feb 18, 2014 9:54 am
At its core, this sentence tests parallel structures and pronoun agreement.

"Geologists have found that streams changed, from X to Y / shifting from X to Y". Either option is correct so long as X and Y are parallel.

The full solution below is taken from the GMATFix App.

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by Joseph_Alexander » Sat Aug 02, 2014 6:28 am
Hi Patrick?

Doesn't the presence of changed and shifting indicate redundancy?
Patrick_GMATFix wrote: "Geologists have found that streams changed, from X to Y / shifting from X to Y". Either option is correct so long as X and Y are parallel.

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by trgtgmat2013 » Tue Oct 14, 2014 10:23 pm
What's the OA??

IMO A.
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by [email protected] » Thu Oct 16, 2014 5:28 pm
Hi trgtgmat2013,

This SC is based entirely on 2-part Parallelism rules, although I'm pretty sure that you already knew that.

The only answer that correct parallels 2 ideas and uses the 2-part phrase "from ____ to _____" correct is Answer A.

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by bonbossamazing » Thu Nov 27, 2014 12:40 am
[email protected] wrote:Hi trgtgmat2013,

This SC is based entirely on 2-part Parallelism rules, although I'm pretty sure that you already knew that.

The only answer that correct parallels 2 ideas and uses the 2-part phrase "from ____ to _____" correct is Answer A.

GMAT assassins aren't born, they're made,
Rich
Boss dont you think that shifting being a verb+ing modifier, modifies the preceding clause subject geologist? Thats the reason why D E are discarded?
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by sagarock » Mon Feb 06, 2017 5:58 am
Hii tutors,can anyone explain why 'to hold' i.e infinitive is correct here and why 'to make' is wrong in second sentence/
1. Geologists have found that streams in the Karoo basin of South Africa changed suddenly at the end of the Permian period 250 million years ago, from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas without deep-rooted vegetation to hold the soil together.

2. Because she knew many of the leaders of colonial America and the American Revolution personally, Mercy Otis Warren was continually at or near the center of political events from 1765 to 1789, a vantage point combining with her talent for writing to make her one of the most valuable historians of the era.
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by Ali Tariq » Mon Feb 06, 2017 8:08 pm
to make in second sentence in not incorrect.
sagarock wrote:Hii tutors,can anyone explain why 'to hold' i.e infinitive is correct here and why 'to make' is wrong in second sentence/
1. Geologists have found that streams in the Karoo basin of South Africa changed suddenly at the end of the Permian period 250 million years ago, from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas without deep-rooted vegetation to hold the soil together.

2. Because she knew many of the leaders of colonial America and the American Revolution personally, Mercy Otis Warren was continually at or near the center of political events from 1765 to 1789, a vantage point combining with her talent for writing to make her one of the most valuable historians of the era.
1. Geologists have found that streams in the Karoo basin of South Africa changed suddenly at the end of the Permian period 250 million years ago, from the meandering shape typically found in well-vegetated zones to the braided pattern found in areas without deep-rooted vegetation to hold the soil together.
implied subject of infinitive (to hold) is streams
streams hold the soil together
Did streams actually hold the soil together,like in literal sense?
NO!
However, streams were responsible for this evantuality; i.e streams is implied subject.
2. Because she knew many of the leaders of colonial America and the American Revolution personally, Mercy Otis Warren was continually at or near the center of political events from 1765 to 1789, a vantage point combining with her talent for writing to make her one of the most valuable historians of the era.
implied subject of infinitive (to make) is a vantage point
vantage point made her one of the most valuable historians of the era
Did vantage point actually made her one of the most valuable historians of the era,like in literal sense?
NO!
However, vantage point was responsible for this evantuality; i.e vantage point is implied subject.

Second sentence is incorrect because of incorrect form of participle
What does verbing imply?
verbing is an active form.
Verbing, therefore, implies that subject of verbing actually did (in literal sense) the action that verbing communicates.

(responsibility is not same as actually doing something in literal sense)

vantage point was combined--> correct
vantage point was combining--> incorrect

using correct participle is an important decision point in GMAT SC.
I cannot stress its importance enough.

can you tell me which participle in following sentence is correct as dictated by CONTEXT?
the irritated/irritating mother finally snaps at her irritated/irritating toddler

clue
[spoiler]mother was irritated or mother was irritating?
toddler was irritated or toddler was irritating?[/spoiler]

correct version
[spoiler]the irritated mother finally snaps at her irritating toddler[/spoiler]
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by sagarock » Tue Feb 07, 2017 12:58 pm
Thank you sir,well explained .lemme follow with some doubts and my lessons that i learnt here.

1.so you are suggesting to hold i.e adverbial modifier is modifying streams.why streams changed...? streams changed to hold..

2.Now coming to ing concept that verb ing should be active that means noun should be the doer of the verb+ing?
Check this sentences
1.The senate publishing report said that it has potential to be game changer.-correct
2.john complaining about food quality...-correct
3.A law prohibiting cow slaughter at public places has just been passed in maharashtra -incorrect i guess

1. Can you gimme more examples in which verb+ing i.e action one can be incorrectly used?

2.So is it always we have to check this ,or only when it is an action verb +ing?.

3..Is this concept also applies to verb+ing plus comma?

4.How does this concept applies to real action verb not ing one ,especially when no
un is a non living thing?
BEcause sometimes i have seen it used correctly.for ex-The water and sugar combine to form syrup.2.The stringent tax reforms and laws by current govt brought corrupt people to their knees.
AND it is also used absurdly.For ex-The plant attacks reindeer.
coming back to your question i instinctively choose right answer without any prior knowledge on this topic but i believe knowing the concept can help me in difficult questions.I will follow up once you post your explanations

ps-sorry for asking so many questions .i believe this thread has potential to help many non natives in future.:)
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by Ali Tariq » Tue Feb 07, 2017 7:59 pm
so you are suggesting to hold i.e adverbial modifier is modifying streams.
why streams changed...?
streams changed to hold...
I suggest that you shift your understanding of the situation under consideration from why? to cause and effect situation and see whether you get the better understanding .
If not, then read what follows...

It seems, as I mentioned, that you believe that infinitives, when used as adverbials, always answer why? or have the connotation of purpose/ intention.

Though it can be the case, but it is not always the case across the spectrum of situations.

It can also show cause effect relationship, even if this relationship is devoid of deliberate/ explicit intention or purpose on the part of entity responsible for effect.

Lets have some example sentences...
groups of teachers combined to tackle a variety of problems
why? Why groups combined?
To tackle problems!
Was their some purpose of this combining?
Yes!
Was their some intention on part of groups of teachers?
Yes! ( intention was to tackle problems )

What was the effect of this combing?
What was the outcome of this combing?
What was the result of this combining?
WE Don't KNOW!

In this sentence, Infinitive adverbial ( to tackle) serves the job of intention/purpose but does not serve the job of causal relationship because, well, its not a causal situation.

Therefore, adverbial infinitive is acceptable here.
It is one of the job of adverbial modifiers to answer WHY?
Adverbials ,similarly, can also answer HOW?
Adverbials, similarly, can also accommodate cause and effect situations and thus infinitive adverbials CAN accommodate cause and effect situations.

In Cause and effect situations you won't get answer to WHY?( wrong question to ask in the first place)

Now lets have a look at another situation in which infinitive adverbial is used again.
2H2O + O2--> 2H20
Can I represent this equation in text form?
YES!
Hydrogen and oxygen combines to form/to make water.
Or
water and sugar combine to form syrup.
What will be the right question to ask?
Why? Why they combine? To make water...
Or
Is this a causal situation?
YES!
Cause-->the act/ process of combining
Effect-->forming of water

Was their some explicit purpose or intention of this combining on part of hydrogen and oxygen?
No!
What was the effect of this combing?
What was the outcome of this combing?
What was the result of this combining?
Water forms as a result

Takeaway:
In why? situation, we can have the intention but we don't necessarily know the outcome.
In causal situation, we may NOT have the intention but we NECESSARILY know the outcome( effect).
You will always be able to tell which situation is this from CONTEXT. CONTEXT dictates, Logic follows
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by Ali Tariq » Tue Feb 07, 2017 8:13 pm
Now have a look at the SC under discussion and apply what we have just discussed...

Streams changed-->effect of this changing is that they(streams) now hold soil together in areas without deep-rooted vegetation whereas earlier soil used to be held together by this particular shape of stream called meandering shape, which is found in well-vegetated zones.

How have streams changed?
From meandering shape to braided shape (what the hell these terms mean, I don't know. Only geologists are supposed to know .HOWEVER their meanings or their purpose should be pretty clear from the CONTEXT. There will be enough clues in the context for me to decipher their meaning sufficient to get the correct understanding of what exactly is going on, and what the author intends to communicate. )

i.e,
Situation before sudden change of shape of streams--> meandering shape (typically found in well-vegetated zones).
This shape/ pattern of stream does not have/ need not have the innate ability to hold soil together.
This job is well served by vegetation/ vegetated zone, in which this stream pattern is found.

Situation after sudden change of shape of streams--> the braided pattern (found in areas without deep-rooted vegetation) .
This shape/ pattern of stream has the innate ability to hold soil together.
This job now is no more served by zone/ area without deep vegetation.
Now, it is well served by this particular pattern of stream)

What is the effect of this sudden change of pattern/shape of stream?
Soil, which used to be held together because of vegetated zone( deep vegetated zone), is now held together because of the particular shape/pattern of stream, and this new pattern/ shape of stream is effect /outcome/ result of sudden change, which occurred many years ago.

Which action/event is responsible for holding the soil together (situation now, at this moment)?
Change, sudden change...
Which entity is the actual performer/ doer of that action?
Streams( nature )

If some action/event has to be held responsible for the eventuality (helding together of soil), it is "the changing( sudden change)"

Similarly ,if some entity( and it can include nature/forces of nature, or any such thing which is incapable of purpose or intention or it ,in turn, can be a situation, eventuality or outcome of some other event or action) has to be held responsible for the eventuality (helding together of soil), it is "streams"(nature / force of nature).

Did streams actually hold soil together, in literal sense?
[spoiler]No![/spoiler]
Was there purpose/ intention on part of streams?
[spoiler]No![/spoiler]
Is there cause and effect relationship?
[spoiler]Yes![/spoiler]
Can to verb show this relationship?
[spoiler]Yes![/spoiler]
Can causal relationship be served even if there is no explicit intention or purpose on part of agent/entity responsible for cause?
[spoiler]Yes![/spoiler]
Can you tell me some other construction in GMAT that can serve somewhat similar job?
Subject verb... ,verbing can serve the same job: causal relationship without explicit intention or purpose on part of agent/entity responsible for cause

Why not use ,verbing (adverbial) here instead of adverbial infinitive?
,verbing has the connotation of SIMULTANEOUS CAUSE AND EFFECT RELATIONSHIP, whereas in the SC under discussion it is explicitly mentioned that it was sudden change of shape: this wording, although it has the connotation of sudden, but in no way it has the connotation of SIMULTANEOUS EFFECT.

Sudden change-->still some time delay, context makes it clear to avoid ambiguity.

What is the relationship between infinitive and Verbing?
Well, both , in English grammar, are called Verbals.
Verbals are derived from verbs but they can never serve as verbs.
Infinitive can serve as noun, verbing can also serve as noun
Infinitive can serve as adjectives, verbing can also serve as adjective (to modify noun)
Infinitive can serve as adverbs, verbing can also serve as adverbs (adverbial/ modifying action)
Infinitives can take direct object, verbing can also take direct object.
note: infinitive, in GMAT, cannot be the direct object of preposition but verbing can be.
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by Ali Tariq » Tue Feb 07, 2017 8:20 pm
Apply same cause and effect relationship in Vantage point scenario

Vantage point was combined with her(Mercy O W) talent for writing to make her one of the most valuable historians of that era.

If some action/event has to be held responsible for the eventuality (making her best) , it is "the combining"

Similarly ,if some entity( and it can include nature/forces of nature, or any such thing which is incapable of purpose or intention or it ,in turn, can be a situation, eventuality or outcome of some other event or action) has to be held responsible for this eventuality (making her valuable historian), it is "Vantage point, a point , place or position that afforded Mercy Otis Warren a good view of political events from 1765 to 1789"(and this point , place or position ,in turn, is a situation, eventuality or outcome of some other event or action (her knowing many of the leaders of colonial America and the American Revolution personally).

Takeaway/ The point of all this discussion:
Go through some more similar situations and you will have enough experience and an experienced eye can spot the patterns.
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by Ali Tariq » Tue Feb 07, 2017 8:41 pm
2.Now coming to ing concept that verb ing should be active that means noun should be the doer of the verb+ing?
1.The senate publishing report said that it has potential to be game changer.-correct

This sentence is incorrect and not for usage the participle.
Look closely and try to spot what error have you made in this sentence.
However, it seems that you now know which participle to use, i.e whether to use past participle or present participle.

You can make a small sentence to be assured.
Construction of this small sentence would be

noun( modifiee) was/were participle(modifier)

senate was publishing report--> correct
or
senate was published report-->incorrect
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by Ali Tariq » Tue Feb 07, 2017 8:44 pm
john complaining about food quality...
John was complaining (about food quality)--> correct!
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by Ali Tariq » Tue Feb 07, 2017 9:09 pm
In Ving, there will be some action or state.
If there is action, someone will be doing that action.
That someone will be subject/modifiee(noun)

There can ONLY be two interpretations
1) subject(modifiee) actually is the doer of that action
or
2) subject( modifiee ) will be responsible for that action.
Only one interpretation will make sense in any situation.
As long as one interpretation makes sense, you are good to go.

SAME GOES FOR ,verbing

SAME GOES FOR prepositional phrase in following construction
subject verb noun prep phrase
prep phrase can modify noun( in that case it is adjectivial)
prep phrase can modify verb( in that case it is adverbial)

whichever interpretation makes sense as dictated by context, you have to pick it up,

3.A law prohibiting cow slaughter at public places has just been passed in maharashtra
As far as the debate that whether to use past partiiple or present participle goes, present participle is used CORRECTLY.

1) Is law actually prohibiting cow slaughter( in an active manner)?
No!
2) Is law responsible for prohibition of cow slaughter? (or does credit goes to law)
Yes!
As second interpretation makes sense, you are good to go.


Therefore,
3.A law prohibiting cow slaughter at public places has just been passed in maharashtra
is correct!



I will list some official questions at the end of discussion so that you be acquainted with GMAC's stance on this issue in much better way.

Takeaway:
between Ved(past participle) and Ving( present participle),
only one will be correct.
They are NOT interchangeable.
It is a valid distinction and thus an important decesion point.

rest your decision on making a small sentence involving noun (modifiee) and participle.
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