I have a question regarding the "milky sap" modifier here. In answer choice A, it seems like the milky sap is the one that causes mouth sores, but in answer choice B, the meaning changes and it is now the plant that causes the mouth sores. Because of this meaning choice I selected A, could someone briefly go over why my thought process was incorrect?

Hiee , can anyone explain

In the correct ans B.

how we can use displaces as the verb to grasses ?

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Hi NinetyFour , LordStark gave you an excellent head start.*

Posts on the thread deal with your question.

Are there parts of those posts that you do not understand?

Essential modifiers can never be removed from a sentence.

Non-essential modifiers can be removed from a sentence.

with milky sap is a non-essential modifier
(1) the phrase is set off by commas, and ONLY non-essential modifiers can be set off by commas.

(2) non-essential modifiers can be removed without changing the core meaning of the sentence

(3) remove the phrase. No kidding.
Take it and the commas out.
"With milky sap" is a prepositional phrase that adds some information.
It is set off by commas. If a modifier is set off by commas, it should be fair game for removal.**

We can also remove the other modifier set off by commas, a . . . plant from Eurasia.

About 5 million acres ... have been invaded by leafy spurge, a ... plant from Eurasia , with milky sap, that gives mouth sores to cattle and displaces grasses and other cattle food, rendering rangeland worthless.

Now we have

... leafy splurge ... that gives mouth sores to cattle and displaces grasses and other cattle food, rendering rangeland worthless.

The guideline is: that-clauses almost always touch the noun that they modify. That guideline is not a hard-and-fast rule, as this official question demonstrates.

Sometimes a descriptive phrase such as "with milky sap" cannot be placed in another part of the sentence. In such cases, it is okay for there to be separation between the noun plant, and its relative pronoun that.

Takeaway: is the information set off by commas?
The commas signal that the modifier is not essential.
Remove the information and the comma(s). See what happens.

In this case, what happens is that the leafy splurge gives mouth sores and displaces grasses.

Hope that analysis helps.


*I think that LordStark was hinting that "with milky sap" does not matter a whole lot to the meaning of the sentence. That hint is correct.

**There are a few exceptions to the comma rule such as dates, which must always be set off by commas. Not to worry. GMAC does not test whether information such as a date is essential.
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Manas1212 , both of your examples are correct.

I think that you are suggesting that we should use logic to figure out
the most likely subject (and causal culprit);
in your examples, the logical culprit is a particular kind of mosquito,
and whether we add the "sting" does not change the causal logic.

In the prompt, the most likely culprit is some hideous plant called "leafy splurge."
What invaded the U.S.? Leafy splurge.
What is likely to be the cause of worthless rangeland? Whatever invaded the U.S.

If you are asking a different question or I have missed your point,
tag me again.
Nice work! +1


(And I just caught an error in my answers: I need to use splurge, the plant's name, not plant.
Plant is in the appositive.)
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Sorry, I'm maniacally late to the party here, but I'll throw in my two cents anyway, even though it's probably too late to be useful.

You're certainly right that (B) changes the meaning of the sentence, but this is not a reason to eliminate an answer choice. You can eliminate an answer choice if it creates an illogical meaning, but just “changing” the meaning isn’t necessarily a crime.

In this case, the question-writer doesn't expect us to come in with any prior information about leafy spurge, so the question about whether it's the plant or the sap that causes the sores can't be the deciding factor. We need to look for other, more concrete decision points.

Take another look at (A):


As several smart people have noted, this construction makes it sound as though "displacing grasses" is a consequence of the milky sap giving mouth sores to cattle. How would giving mouth sores to cattle make grass disappear? This makes no sense. And because this modification is illogical, (A) is out.

Takeaway: if one of the answer choices changes the original meaning, but it's better, that's a good thing.

I hope that helps!
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In this case, the clause beginning with "that" is a relative clause that modifies "a herbaceous plant from Eurasia." This relative clause has a subject, "that," which clearly goes with the verbs "gives" and "displaces," just as the the noun "plant" does in the following clause. The plant gives mouth sores to cattle and displaces grasses.

So, while repeating "that" would not make the sentence clearly incorrect, there is no need to repeat "that."

So, when do we have to repeat "that"? We have to repeat "that" when the meaning that we want to convey would not be effectively conveyed unless "that" were repeated.

Consider the following sentences.

I told John that I had seen a man peering into the windows of the building and that the man had been wearing a blue hat.

I told John that I had seen a man peering into the windows of the building, and the man had been wearing a blue hat.

These two sentences are pretty similar, but mean different things.

The first conveys that I told John two things, that I had seen a man and that the man had been wearing a blue hat.

The second contains only one "that," and so, it conveys that I told John one thing, that I had seen a man, and it conveys that, in addition to my telling John about the man, the man had been wearing a blue hat. Because the second "that" is not included, the sentence does not convey that I told John that the man was wearing a blue hat.

Either version is correct, but they convey different things. So, if you want to convey that I told John two things, you have to use "that" twice.

Overall, it helps to realize that analyzing parallel structures tends to be more about considering logic and effectiveness of expression than about checking to see whether a structure is constructed according to some rule.
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Sorry for my horribly belated reply, saurabh9gupta!

There's a pretty long rant about "having + verb" constructions in this transcript from our old verbal chats. The essence is basically what you suggested above: "having + verb" basically has to indicate the first of two actions.

For example, we could say "Having been angry all morning, Charlie ate a third breakfast and subsequently behaved more reasonably." That's fine, since "having been angry" was an action that Charlie "performed" before he ate his third breakfast.

I don't think there's a ton of value in contorting the original sentence to make "having been" work. But I'll give it a shot with a stripped-down version of the sentence, anyway: "Having been invaded by leafy spurge, about 5 million acres in the United States became unpalatable to cattle." In this version, the 5 million acres were invaded by leafy spurge first, and became unpalatable to cattle later. Fair enough.

I hope this helps a bit!
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I have a doubt in this question.

About 5 million acres in the United States have been invaded by leafy spurge, "a herbaceous plant from Eurasia with milky sap that gives mouth sores to cattle", displacing grasses and other cattle food and rendering rangeland worthless.

Isn't the quoted part a non-essential part of the sentence as it describes something on the spurge. Because if it is,then, the comma before and after the non essential can be erased with the non-essential modifier itself, giving rise to the following statement


About 5 million acres in the United States have been invaded by leafy spurge displacing grasses and other cattle food and rendering rangeland worthless.

Where displacing is modifying spurge.

I also a a doubt that the non-essential is more than a phrase because of verb "gives" is present in it

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What's up Marty? Good to see that Target Test Prep now has a verified perfect 800 GMAT scorer on its team.

-Brian
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