Active underwater faults are observed carefully, tectono

Question

Active underwater faults are observed  carefully, tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust.

A. carefully, tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust

B. carefully, whereas tectonophysicists monitor the physical processes that underlie tectonic formation to predict the Earth’s crust’s movements

C. carefully; the physical processes that underlie tectonic formation are monitored by tectonophysicists so that they can predict the movements of the Earth’s crust

D. carefully; tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust

E. by tectonophysicists who carefully monitor the physical processes that underlie tectonic formation to predict when the movement of the Earth’s crust occurs

mikemcgarry · Accepted Answer

Dear avohden , I'm happy to help with this. :-)

This is a great question. First of all, notice that (A) is a run-on sentence. See: https://gmat.magoosh.com/lessons/916-run-on-sentences We have to figure out to relate the two independent clauses. Choice (B) uses " whereas ", which is grammatically correct, but logically, this doesn't work. We don't want a contrast between the two independent clauses --- they don't contradict, but rather, reinforce each other. This is wrong. For more on " whereas ", see: https://magoosh.com/gmat/2013/gmat-idiom ... ed-idioms/ Choice (C) uses a semi-colon to separate the independent clauses, a perfectly correct arrangement, but for some reason, the second clause gets recast in the passive, which is very awkward. This is wrong. Choice (D) also correctly uses a semicolon and keeps both clauses active. This is very promising. Choice (E) makes the " fit 10 lbs of Spam in a 5 lb bag " mistake. This version tries to fit everything into nested clauses & phrases of a single all-encompassing clause. All one run, without so much as a comma. Try to say all of (E) in one breath! It's a distended disaster. There is no way this could possibly be correct. The only possible answer is (D) . Does all this make sense? Mike :-)

mikemcgarry · Answer

Dear 282552 , I'm happy to respond. :-)

Put simply, choice (E) is awkward. Notice that the prompt, (A) , has two full independent clauses --- the mistake there is that it's a run-on sentence, with no proper conjunction or way to relate the two clauses. Nevertheless, there are two full clauses of information there. As a general rule, if you take two full independent clauses and try to combine them into one by making a long series of subordinate phrases and clauses, that's going to be awkward. Part of what is awkward is the negotiation of the passive construction. In the original, Active underwater faults are observed carefully .... the passive is about " active underwater faults " and no subject is specified --- that's the ideal condition in which to use the passive. This is perfectly correct. By contrast, (E) adds a subject, Active underwater faults are observed carefully by tectonophysicists .... Once we have to specify a subject, it raises the question whether passive construction is the best choice. There is something indirect and inefficient about this construction now. See: https://magoosh.com/gmat/2012/active-vs- ... -the-gmat/ Also, there's a subtle difference in meaning between (1) to predict the movements of the Earth’s crust (2) to predict when the movement of the Earth’s crust occurs The first is what the prompt & the OA have. The second is what (E) has. Even if they had the same meaning, the second is wordier, but they don't even have the same meaning. The first implies a general prediction of patterns and trends, whereas the second implies prediction down to a specific clock time!! Furthermore, even if the second were logically correct, why is the verb " occurs " in the present tense? Since it's a prediction, the tense should be in the future. The second is wordy, has the wrong verb tense, and changes the meaning --- it's a trainwreck disaster of a choice. Choice (E) is loaded with problems and mistakes. That's why it's wrong. Does this make sense? Mike :-)

282552 · Answer

Mike
I am sorry to ask again but can you please explain ,in detail, why do you discard option E.

virinchiwiwo · Answer

Hi Mike, (Others, please feel free to chime in)

Regarding option 'C', the official explanation says that 'they' can refer to faults or tectonophysicists. However, in my opinion its clearly pointing to 'tectonophysicists', as it appears right after that word. Please correct me if I am wrong in thinking so.

2. The problem regarding passive voice: The first part of the sentence is in passive voice, so by re-arranging the second part of the sentence to passive voice, wouldn't we make it parallel and shouldn't that be more suitable?

In general, how do we pick out the 'parallelism' errors in sentences and why can't this sentence be qualified as a sentence which has 'parallelism' error? Thank you

mikemcgarry · Answer

Dear virinchiwiwo I'm happy to respond. :-)

Here's the sentence again, with choice (C) . Active underwater faults are observed carefully, tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust . (C) carefully; the physical processes that underlie tectonic formation are monitored by tectonophysicists so that they can predict the movements of the Earth’s crust First of all, the pronoun " they " and its antecedent. It's true, we can figure out using logic that the antecedent should be " tectonophysicists ", but the grammar doesn't clearly indicate that. A sentence in which grammar and logic are not saying the same thing is not a well written section. If we have to use logic to answer a question that grammar leaves unclear, that is a poorly written sentence. That's the problem with " they ." Now, when a sentence is split by a semicolon, there is no expectation that the two halves of the sentence will be in parallel. In particular, the decision whether to use passive voice should be based on whether that is an appropriate choice in either case. If we had two verbs of the same subject, in parallel, then it would make more sense to bring the elements into parallel structure, but here, it's inappropriate. In the first half, the subject is unknown: we know what is " observed ", but who is doing the observing is something that we don't know, nor is the answer to that question at all relevant. That's the idea conditions for passive voice. In the second half, we know the subject, so in passive voice we have to stick the subject in a " by " prepositional phrase. That is exactly when we do not want to use the passive voice. The combination of these two is why (C) is a disastrous choice. Does this make sense? Mike :-)

sathyadev09 · Answer

Great post mike. Two verbs referring to the same subject is one of the conditions that drives parallelism. That makes perfect sense.

I am curious to know how a sentence would look if 'they' in the sentence had to point to the physicists in a grammatically correct fashion?

For the passive voice : you mentioned that by using passive voice, we must use 'by' with the subject. Why is the use of 'by' for a subject grammatically wrong in this case? Does this apply to all cases in general?

Thanks & Regards

Sathya

mikemcgarry · Answer

Dear Sathya , First of all, in order for the " they " to refer unambiguously to the " tectonophysicists ," the " tectonophysicists " would have to appear closer to the pronoun, and the " physical processes " would have to be moved somewhere else in the sentence. In other words, we would have to overhaul the entire sentence in order to create one in which the use of the pronoun would be OK. That's simply not worth the work. In practicing SC problems, you can find tons of examples in which pronouns are used correctly and many more in which pronouns are not used correctly. There's absolutely no reason to rewrite this sentence completely for an arbitrary exercise. Also, this is a very important distinction. In passive structure, we indicate the "doer", the original subject, in a "by"-prepositional phrase. That is grammatically correct 100% of the time. It is grammatically correct in choice (C) here. The problem is: the GMAT SC is not simply about grammar. Folks who focus exclusively on grammar totally miss the point of the GMAT SC. The issues of Logic and Rhetorical Construction are just as important as, if not more important than, grammar. For more on these, see: https://magoosh.com/gmat/2013/logical-pr ... orrection/ https://magoosh.com/gmat/2013/rhetorical ... orrection/ The passive structure that appears on wrong answers on the GMAT is often 100% grammatically correct, but rhetorically, it is no good: it is weak, indirect, and wishy-washy, not clear, direct, and powerful. Consider these two sentences. (a) The agreement of Hydromax with Perchlorin Industries was terminated by the CEO of Hydromax, and this termination cased the stocks of Perchlorin to decline in a sudden and rapid manner . (b) Hydromax's CEO terminated the agreement with Perchlorin Industries, causing Perchlorin's stocks to plummet . The first sentence is 100% grammatically correct. If you are judging only on the basis of rules of grammar, that is a perfectly correct sentence. Of course, on the GMAT, the second could be an acceptable sentence, but the first would never stand a chance of being correct. The first one, while 100% grammatically correct, is a rhetorical nightmare: it is way too long, too wordy, too indirect, and too weak. By comparison, the second version is direct, crisp, and powerful. The different has absolutely nothing to do with the rules of grammar, because both are grammatically correct. What I was saying was: in a passive situation in which we don't know, and don't care about, the doer, then that's a very natural situation in which the passive construction might be rhetorically acceptable. The corporate agreement was terminated . Simple and direct. We don't have a doer, and we don't need one. The problem is: when the doer is known, then passive construction involves stuffing the doer into a " by "-preposition. That's 100% grammatically correct, but it almost always makes the sentence longer, more indirect, and weaker. While grammatically correct, it usually produces a rhetorical loser. Not always, but usually. That's precisely why it's important to be suspicious of the passive voice. See: https://magoosh.com/gmat/2012/active-vs- ... -the-gmat/ Does all this make sense? Mike :-)

Kconfused · Answer

Mike,
Thanks for that explanation on why 'Passive' on Gmat is unacceptable. One of the finest distinctions!

gauravkaushik8591 · Answer

In Option D -

'physical processes that underlie tectonic formation to predict the movements'

this sounds as if the processes predict the movements.

please correct me if i'm wrong.

mikemcgarry · Answer

Dear gauravkaushik8591 , I'm happy to respond. :-)

With all due respect, I have to disagree with you. I believe part of the problem is quoting simply a fragment of the sentence --- a sentence fragment doesn't necessarily allow for any sensible interpretation. Grammar & logic are all about context. Part of the problem might be also be a lack of comfort with the infinitive of purpose . See this blog: https://magoosh.com/gmat/2014/the-infini ... orrection/ Consider this series: (a) tectonophysicists do things to predict the movements of the Earth’s crust (b) tectonophysicists monitor the physical processes to predict the movements of the Earth’s crust (c) tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust All three of those are grammatically and logical correct; the third, of course, is what appears in the OA, (D) . You see, a natural place for the infinitive of purpose in a sentence is after the direct object of the verb. A did X to do Y . All three of the sentences above have this structure. It's just that, in the third verb, the direct object was modified by a modifying clause, an adjectival clause, and that made the sentence longer and more complicated, moving the infinitive of purpose even further from the subject & verb. Nevertheless, that's precisely typical of what the GMAT does all the time --- they love packing all kinds of modifying phrase and clauses into the sentence, so that the subject is separated from the verb, so that parallel elements are far apart, etc. etc. By adding "fluff", they try to obscure the fundamental logical structure of the sentence. Indeed, one of the very worst mistakes you can make in looking at a GMAT SC question is just to grab some fragment of the sentence, some particular region, and insist on making sense of that one piece apart from the whole, because any one piece might only have one branch of the parallelism, or the verb but not the subject, or etc. Don't be fooled by the "fluff" --- the primary task of GMAT SC is to identify the deep logical structure of the sentence. Does all this make sense? Mike :-)

jjindal · Answer

Hi Mike,

In 'C', the first clause is in passive voice, 'active faults are observed' so the second clause also needs to be in passive to maintain the necessary parallelism, could you please point a flaw in my understanding?

Thanks in advance.

mikemcgarry · Answer

Dear jjindal , I'm happy to respond. :-)

My friend, what you think is a very common mistake that derives from a misunderstanding of the nature of parallelism. Parallelism is NOT primarily a grammatical structure. Parallelism is a logical structure, and the grammar simply follows the logic. Folks who think of parallelism purely in terms of grammar mistakenly believe that all the grammatical forms must be in mechanical lockstep. This is simply not true. It's true that parallelism is a pattern of matching, but the primary matching is at a logical level, and the grammar merely reflects this enough to make the logic clear. See this blog article: GMAT Grammar Rules: Parallelism and Verb Tenses If two verbs or two clauses are in parallel, the verbs can take any form. We can have active in parallel with passive. We can have any one tense in parallel with any other tense. If the verbs don't share the same subject, then one can be singular and one can be plural. One could be subjunctive and the other not subjunctive. If two clause are in parallel, one could be very short, just 4-5 words, and the other could have all kinds of modifying phrases & clauses. It's a huge mistake to think about parallelism mechanically, as if the matching has to extend down to every detail. The GMAT loves to nail folks who understand parallelism that way. Does all this make sense? Mike :-)

rahul202 · Answer

Change of meaning

brs1cob · Answer

i got the correct answer in 1:11 minutes.

first round of elimination : 2 independent clauses. so we need semi-colon, A and B out.
2nd round of elimination : active voice is preferred and parallelism is required when it comes to active voice. hence E and C are eliminated.

D is a clear winner.

ruchik789 · Answer

D) carefully; tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth’s crust
In the correct answer choice that points to a plural noun processes. Is it acceptable? Can we use that for plural nouns?

sumitkrocks · Answer

E has no issue but it changes the intended meaning.. By putting when... 
Hence, D wins.. Others have issues with the structure... 
C is in passive voice + not conscise ..D is a better choice among all

Posted from my mobile device

Bunuel · Answer

VERITAS PREP OFFICIAL EXPLANATION:

The correct answer is (D). As written, the original sentence is a run-on. (D) correctly joins the independent clauses with a semicolon. (B) corrects the run-on, but “whereas” does not appropriate relate the ideals in the sentence. (C) corrects the run-on, but creates a pronoun reference error - does "they" refer to tectonophysicists or physical processes? . (E) corrects the run-on but in addition to creating a stylistically awkward question it also introduces a slight logical error with the word "when" and the verb "occurs" - the physicists should really predict when the movements (which should also be plural) "will occur". (D) is therefore correct.

Mo2men · Answer

Dear  GMATGuruNY

In the OA choice D, does the phrase  'to predict the movements of the Earth’s crust reflect'  as if the  'processes predict the movements' ?

In the following OG2018

In choice B, 'to run on cleaner-burning natural gas' sound if 'trucks are power to run on...'

So can't question be at hand treated same logic?

GMATGuruNY · Answer

Generally, an infinitive modifier following a clause serves to express INTENT.

B in the second SC:
 The United Parcel Service plans to convert its trucks that are powered by gasoline  to run ... 
Here, the trucks are not performing an action.
The usage of a passive verb --  are powered  -- implies that someone DESIGNED the gasoline-powered trucks.
As a result, a reader might logically construe that the infinitive modifier in red expresses the intent of the TRUCK DESIGNER -- that the trucks ARE POWERED because their designer intended them TO RUN in a particular way.
The intended meaning of the original sentence is that the UNITED PARCEL SERVICE intends the trucks to run in a particular way.
Since both interpretations are logical, eliminate B.

D in the Veritas SC:
 Tectonophysicists monitor the physical processes that underlie tectonic formation  to predict  the movements of the Earth’s crust .
Here,  physical processes  cannot have an intent.
As a result, only one interpretation is possible: the infinitive modifier in green must express the intent of the  tectonophysicists .

Active underwater faults are observed carefully, tectono

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Active underwater faults are observed carefully, tectono

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