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To map Earth's interior, geologists use a network of seismometers to 09 Jun 2021, 20:50
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ashmit99
Because it is said that GMAT is not a grammar test.
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Hi ashmit99,

My reply is not specific to this question, but while it is true that the GMAT wants to test reasoning skills, knowledge of grammar does get tested (indirectly). In the quantitative section we wouldn't really want to ignore the basic concepts and formulae just because the GMAT wants to test our reasoning skills, right? Not unless we're already very familiar with those concepts.
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To map Earth's interior, geologists use a network of seismometers to 09 Jun 2021, 23:56
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To map Earth's interior, geologists use a network of seismometers to chart seismic waves that originate in the earth's crust and ricochet around its interior, most rapidly traveling through cold, dense regions and slower through hotter rocks.


(A) interior, most rapidly traveling through cold, dense regions and slower

(B) interior, which travel most rapidly through cold, dense regions, and more slowly

(C) interior, traveling most rapidly through cold, dense regions and more slowly

(D) interior and most rapidly travel through cold, dense regions, and slower

(E) interior and that travel most rapidly through cold, dense regions and slower




EducationAisle VeritasKarishma GMATNinja

Why is B incorrect? Why can't which refer to waves? I think it can.


He has a room full of chocolates, which is on ground floor.

Here which is referring "room."

Thanks!
Show more

The use of which is a problem. The noun it refers to is far away. It may be the only logical noun that it can refer to but it makes the sentence confusing. So then, is there a better option available? Yes, (C) is superior. The present participle "travelling" refers to the subject of the previous clause "that" which stands for "seismic waves". All good.

Also, I have an issue with the comma before "and" in option (B).

"and" joins "most rapidly through..." and "more slowly through..."
It is not joining two independent clauses with their own subjects and verbs and neither is it joining the last element of a list. Hence, a comma before "and" is not justified. Normally, I may not worry too much about punctuation but in option (C), the comma has been removed.

Hence option (C) is superior on both counts.
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To map Earth's interior, geologists use a network of seismometers to 10 Jun 2021, 00:10
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To map Earth's interior, geologists use a network of seismometers to chart seismic waves that originate in the earth's crust and ricochet around its interior, most rapidly traveling through cold, dense regions and slower through hotter rocks.


(A) interior, most rapidly traveling through cold, dense regions and slower

(B) interior, which travel most rapidly through cold, dense regions, and more slowly

(C) interior, traveling most rapidly through cold, dense regions and more slowly

(D) interior and most rapidly travel through cold, dense regions, and slower

(E) interior and that travel most rapidly through cold, dense regions and slower




EducationAisle VeritasKarishma GMATNinja

Why is B incorrect? Why can't which refer to waves? I think it can.


He has a room full of chocolates, which is on ground floor.

Here which is referring "room."

Thanks!

The use of which is a problem. The noun it refers to is far away. It may be the only logical noun that it can refer to but it makes the sentence confusing. So then, is there a better option available? Yes, (C) is superior. The present participle "travelling" refers to the subject of the previous clause "that" which stands for "seismic waves". All good.

Also, I have an issue with the comma before "and" in option (B).

"and" joins "most rapidly through..." and "more slowly through..."
It is not joining two independent clauses with their own subjects and verbs and neither is it joining the last element of a list. Hence, a comma before "and" is not justified. Normally, I may not worry too much about punctuation but in option (C), the comma has been removed.

Hence option (C) is superior on both counts.
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Makes sense. Also, do you think the verb-ing modifier in the correct option makes sense with only the subject of previous clause? or the whole previous clause?

While attempting the question, I was trying to link the verb ing to previous clause. But I wasn't sure how would that make sense? Can you please elaborate a bit on the use of verb-ing?

Thanks!
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To map Earth's interior, geologists use a network of seismometers to 10 Jun 2021, 00:13
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However, don't you think "which" wouldn't make sense with interior or curst? Because interior or crust can't travel.
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Absolutely! And that's precisely the reason why this is not a great construct Ashmit.

Quote:

We've seen a lot of cases where which or that has two antecedents but logically they would refer to only one. Now, my point is we only see logical antecedents in GMAT right? Because it is said that GMAT is not a grammar test.
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Well, which pretty much always looks at only the grammatical antecedent. that is more flexible in this regard.

p.s. Our book EducationAisle Sentence Correction Nirvana discusses "which" vs "that", its application and examples in significant detail. If you or someone is interested, PM me your email-id; I can mail the corresponding section.
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To map Earth's interior, geologists use a network of seismometers to 10 Jun 2021, 00:45
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Makes sense. Also, do you think the verb-ing modifier in the correct option makes sense with only the subject of previous clause? or the whole previous clause?

While attempting the question, I was trying to link the verb ing to previous clause. But I wasn't sure how would that make sense? Can you please elaborate a bit on the use of verb-ing?

Thanks!
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It makes sense with the verb closest to it - "seismic waves ricochet around its interior".
So the waves bounce around the interior, travelling rapidly through cold regions and slowly through hot.

Check here to read up on present participles:
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2014/1 ... -the-gmat/
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2014/1 ... modifiers/
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To map Earth's interior, geologists use a network of seismometers to 10 Jun 2021, 01:13
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ashmit99


Makes sense. Also, do you think the verb-ing modifier in the correct option makes sense with only the subject of previous clause? or the whole previous clause?

While attempting the question, I was trying to link the verb ing to previous clause. But I wasn't sure how would that make sense? Can you please elaborate a bit on the use of verb-ing?

Thanks!

It makes sense with the verb closest to it - "seismic waves ricochet around its interior".
So the waves bounce around the interior, travelling rapidly through cold regions and slowly through hot.

Check here to read up on present participles:
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2014/1 ... -the-gmat/
https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2014/1 ... modifiers/
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Now it makes sense. Didn't know the meaning of ricochet. Maybe that's why wasn't able to pick it up.

Thanks, VeritasKarishma EducationAisle
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To map Earth's interior, geologists use a network of seismometers to 16 Jul 2021, 02:30
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GMATNinja, I tried to look for my doubt in this long long long thread, but I couldn't spot it, so I thought of asking you directly.

Would you say that the way option E is framed it conveys the meaning that there are two kinds of seismic waves that the seismometers are trying to chart : 1."that originate...interior" 2. "that travel most....rocks".?

It is on this basis that I crossed out E. Also, I am not 100% sure whether "most rapidly" can go with "slower". Certainly, option C with "most rapidly...more slowly" sounds better, but I am not sure if E is wrong because of this parallelism error.
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To map Earth's interior, geologists use a network of seismometers to 13 Aug 2021, 08:25
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GMATNinja, I tried to look for my doubt in this long long long thread, but I couldn't spot it, so I thought of asking you directly.

Would you say that the way option E is framed it conveys the meaning that there are two kinds of seismic waves that the seismometers are trying to chart : 1."that originate...interior" 2. "that travel most....rocks".?

It is on this basis that I crossed out E. Also, I am not 100% sure whether "most rapidly" can go with "slower". Certainly, option C with "most rapidly...more slowly" sounds better, but I am not sure if E is wrong because of this parallelism error.
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I don't think (E) necessarily implies that there are two kinds of seismic waves. To illustrate why, consider this example:

    "Tim enjoys music (1) that is very loud and (2) that lacks originality."

Both (1) and (2) describe the kind of music that Tim enjoys. If we instead wanted to emphasize that Tim likes two DISTINCT buckets of music, it would be better to write, "Tim enjoys (1) music that is very loud and (2) music that lacks originality."

Similarly, if we wanted to suggest that there are two types of seismic waves, that meaning would be more clearly expressed with, "... geologists use a network of seismometers to chart (1) seismic waves that originate in the earth's crust and ricochet around its interior and (2) seismic waves that travel most rapidly through..."

As for the parallelism...

  • Yes, (C) certainly looks/feels/sounds much better with the symmetrical set of adverbs ("most rapidly" and "more slowly").
  • But instead of analyzing the parallelism in (E) from a purely technical standpoint, try thinking about what the word "slower" suggests from a meaning perspective: it implies that there is some sort of comparison, and leaves the reader wondering, "Slower than what or when?"
  • For example, it would be okay to write something like, "... waves that travel slower through hotter rocks THAN through cold, dense regions," but that's not what we have in (E).
  • So yes, "more slowly" certainly looks/feels/sounds more parallel in this case. But more importantly, it's more appropriate from a meaning perspective.

(C) is definitely the better choice. (For another vote against (E), notice that "and" shows up THREE times -- this isn't necessarily WRONG, exactly, but makes it awfully hard for the reader to keep all of the parallelism straight.)

I hope that helps!
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To map Earth's interior, geologists use a network of seismometers to 13 Aug 2021, 19:55
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EMPOWERgmatVerbal
Hello Everyone!

Let's take a closer look at this question, one issue at a time, and narrow it down to the correct answer! First, here is the original question with any major differences between the options highlighted in orange:

To map Earth's interior, geologists use a network of seismometers to chart seismic waves that originate in the earth's crust and ricochet around its interior, most rapidly traveling through cold, dense regions and slower through hotter rocks.

(A) interior, most rapidly traveling through cold, dense regions and slower
(B) interior, which travel most rapidly through cold, dense regions, and more slowly
(C) interior, traveling most rapidly through cold, dense regions and more slowly
(D) interior and most rapidly travel through cold, dense regions, and slower
(E) interior and that travel most rapidly through cold, dense regions and slower

After a quick glance over the options, there are a few places we can focus on:

1. most rapidly traveling / travel most rapidly / traveling most rapidly / most rapidly travel
2. slower / more slowly
3. comma vs. no comma before "and"

Since #1 on our list seems a bit complicated, let's start with #2 on our list because it should eliminate 2-3 options quickly. This is an issue of parallelism, so let's make sure the two adverbs are written using the same structure:

(A) interior, most rapidly traveling through cold, dense regions and slower
(B) interior, which travel most rapidly through cold, dense regions, and more slowly
(C) interior, traveling most rapidly through cold, dense regions and more slowly
(D) interior and most rapidly travel through cold, dense regions, and slower
(E) interior and that travel most rapidly through cold, dense regions and slower

We can eliminate options A, D, & E because they don't use parallel structure when describing the two speeds a seismometer travels in different conditions.

Now that we have it narrowed down to only 2 options, let's see if we can find any other problems to eliminate one of these options, leaving us with the correct choice:

(B) interior, which travel most rapidly through cold, dense regions, and more slowly

This is INCORRECT for two reasons. First, using the comma + which creates a modifier that must refer back to the nearest preceding noun. In this case, that noun is "interior," which isn't what's traveling - the seismometer is! Second, there shouldn't be a comma before the "and" here. It's connecting two dependent clauses together, so it doesn't need a comma. We only use ",and" when connecting two independent clauses or when introducing the last item in a list. Since this is neither of those instances, it's not necessary.

(C) interior, traveling most rapidly through cold, dense regions and more slowly

This is CORRECT! It's clear that the phrase that begins with "traveling" is referring back to the seismometer, it uses parallel structure (rapidly/slowly), and it doesn't have that extra comma before "and."


There you have it - option C is the correct choice!


Don't study for the GMAT. Train for it.
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How does "traveling" modify seismometer? Shouldn't it modify waves? How does the seismometer travel?
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To map Earth's interior, geologists use a network of seismometers to 06 Sep 2021, 11:28
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In option C, shouldn't we have to use "than" after we have used the comparative marker "more"?
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To map Earth's interior, geologists use a network of seismometers to 01 Nov 2021, 11:08
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Hello GMATNinja,

I eliminated option C because the "more slowly" did not make sense to me.
The waves move most rapidly through A and "more slowly" through B.
I figured we'd need something to compare to here, something that was moving "less slowly", in order to warrant the use of "more slowly".
For example, "The snail moved more slowly than the sloth".
I understand that the "most rapidly" does refer to less slow movement, but this effectively means the waves moved more slowly through B than as quickly as they did through A.
Not sure how well I'm explaining this, but could you please help clear the air and explain why this usage is okay? Option C just seemed off to me because of this.
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To map Earth's interior, geologists use a network of seismometers to 02 Nov 2021, 01:24
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Hello GMATNinja,

I eliminated option C because the "more slowly" did not make sense to me.
The waves move most rapidly through A and "more slowly" through B.
I figured we'd need something to compare to here, something that was moving "less slowly", in order to warrant the use of "more slowly".
For example, "The snail moved more slowly than the sloth".
I understand that the "most rapidly" does refer to less slow movement, but this effectively means the waves moved more slowly through B than as quickly as they did through A.
Not sure how well I'm explaining this, but could you please help clear the air and explain why this usage is okay? Option C just seemed off to me because of this.
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Hello ShreyasJavahar,

We hope this finds you well.

Having gone through the question and your query, we believe we can help resolve your doubt.

To clear up this issue, it is important to understand exactly what this sentence conveys; the meaning conveyed by the relevant part of the sentence is that the seismic waves move at the greatest speed when traveling through cold, dense regions, and they move at a lower speed when traveling through hotter rocks. Thus, we can see that it is speed being compared here, so "most rapidly" and "more slowly" are correct terms to use here. "most rapidly" refers to the waves' highest speed, and "more slowly" refers to any speed lower than that.

We hope this helps.
All the best!
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To map Earth's interior, geologists use a network of seismometers to 09 Nov 2021, 09:27
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ShreyasJavahar
Hello GMATNinja,

I eliminated option C because the "more slowly" did not make sense to me.
The waves move most rapidly through A and "more slowly" through B.
I figured we'd need something to compare to here, something that was moving "less slowly", in order to warrant the use of "more slowly".
For example, "The snail moved more slowly than the sloth".
I understand that the "most rapidly" does refer to less slow movement, but this effectively means the waves moved more slowly through B than as quickly as they did through A.
Not sure how well I'm explaining this, but could you please help clear the air and explain why this usage is okay? Option C just seemed off to me because of this.
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Well, the first thing you'd want to note here is that, meaning-wise, there's not much difference between "slower" and "more slowly." Put another way, "the snail moved slower than the sloth" conveys the same information as your example. So if "more slowly" were illogical here, "slower" would be too, leaving us with 5 incorrect options!

Good rule of thumb: any thought process that causes you to eliminate everything must be flawed. :)

But to see why this usage is okay, it might be helpful to consider a simpler example:

    Tim is happier when his kids do their homework, and sadder when they punch him in the kidneys.

You could interpret this as a direct comparison between how Tim feels when his kids do homework and how he feels when they hit him. And you could also interpret this as Tim having some baseline state that isn't explicitly mentioned. He can be happier than that baseline state or sadder, depending on context. Either interpretation is perfectly logical, and is similar to what we see in this question.

We could, for instance say that the waves travel more slowly through hotter rocks than they travel through through the interior. Or we could say that they travel more slowly through hotter rocks than they usually do. Either interpretation makes sense, so you wouldn't want to agonize over it. Instead, move on to other issues.

I hope that clears things up!
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To map Earth's interior, geologists use a network of seismometers to 13 Dec 2021, 08:27
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if option E is "interior and that travel most rapidly through cold, dense regions and slowly" instead of "(E) interior and that travel most rapidly through cold, dense regions and slower", Then E will be better choice or not?

experts please help.
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To map Earth's interior, geologists use a network of seismometers to 14 Feb 2022, 22:38
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I arrived at the answer without an issue, but I'm wondering why in this question we are separating "most rapidly through cold, dense regions" with a comma? Isn't this technically a list of two items, or am I missing something here? In other words shouldn't be most rapidly through cold and dense regions?
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To map Earth's interior, geologists use a network of seismometers to 14 Feb 2022, 22:43
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Vordhosbn
I arrived at the answer without an issue, but I'm wondering why in this question we are separating "most rapidly through cold, dense regions" with a comma? Isn't this technically a list of two items, or am I missing something here? In other words shouldn't be most rapidly through cold and dense regions?
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Hi Vordhosbn,

We can separate coordinate adjectives with either a comma or an and. For example, we could go with something like:

1. ... the talented, culturally-diverse set of students in the class...
or
2. It was a cold, dark room, but the interviewer had a warm, welcoming smile.

Or we could use an and in between the adjectives.
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To map Earth's interior, geologists use a network of seismometers to 15 Feb 2022, 06:50
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Vordhosbn
I arrived at the answer without an issue, but I'm wondering why in this question we are separating "most rapidly through cold, dense regions" with a comma? Isn't this technically a list of two items, or am I missing something here? In other words shouldn't be most rapidly through cold and dense regions?
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Hello Vordhosbn,

We hope this finds you well.

To answer your query, commas can be used to list two adjectives that modify the same noun together into a list.

For example, "Emily has a big, red-furred dog."

Here, the adjectives "big" and "red-furred" both modify "dog", so they can be joined with a comma to convey that the dog is both big and red-furred.

We hope this helps.
All the best!
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natheodore
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To map Earth's interior, geologists use a network of seismometers to 24 Mar 2022, 09:10
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I still do not understand this. Isn’t that modifying seismic waves, thus there is no clause as per what the experts are saying?? Pls help!’

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To map Earth's interior, geologists use a network of seismometers to 24 Mar 2022, 17:57
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natheodore
I still do not understand this. Isn’t that modifying seismic waves, thus there is no clause as per what the experts are saying?? Pls help!’
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Hi natheodore,

I'm not sure which expert reply or replies you're referring to, but the main (independent) clause here is geologists use... (geologists is the subject, and use is the verb). This sentence also uses a dependent clause (that originate and ricochet; that is the subject, and originate and ricochet are the verbs) to describe seismic waves.

1. ... geologists use a network of seismometers to chart seismic waves that originate in the earth's crust and ricochet...
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To map Earth's interior, geologists use a network of seismometers to 25 Mar 2022, 14:27
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natheodore
I still do not understand this. Isn’t that modifying seismic waves, thus there is no clause as per what the experts are saying?? Pls help!’

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I'm not 100% sure that I understand your question fully, but have you tried reviewing this post?

Yes, the "that" modifies "seismic waves," but "that originate in the earth's crust and ricochet around its interior" IS a clause. The implied subject of that clause is "seismic waves" (represented by the pronoun "that"), and the verb is "originate."

The "-ing" modifier ("traveling most rapidly through cold dense regions") logically modifies the "that" clause that comes right before it.

I hope that helps!
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