About 5 million acres in the United States have been invaded by leafy

Hello sobby,

I would be glad to help you resolve your doubt.

Let me bring in here the sentence with Choice B:

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 and displaces grasses and other cattle food, rendering rangeland worthless.

In the above-mentioned sentence, it is the phrase with milky sap that has been enclosed between two commas. If we were to remove this phrase from the sentence, we would also remove the comma before with and the comma after sap. Hence, it is not so that the that clause is preceded by a comma.

The placement of the phrase with milky sap between the two commas implies this is just an additional information. The milky white sap does not necessarily give mouth sore to the cattle. It is the plant that does so.

Now let's talk about how that correctly modifies the noun entity a herbaceous plant. There is no issue in that modifying a herbaceous plant because the phrase from Eurasia modifies a herbaceous plant and cannot be placed anywhere else in the sentence. Here we see the case of a noun modifier modifying a slightly far away noun. We have a detailed article named Noun Modifiers can Modify slightly far away noun that deals with this concept. This article can be reviewed in the following link:
https://gmatclub.com/forum/noun-modifiers-can-modify-slightly-far-away-noun-135868.html


Hope this helps.
Thanks.
Shraddha

Hi Shraddha Thanks for clarification.

I have one question for choice B. "that" after the non-vital modifier "with milky sap" what does it refer to, logically it should refer to leafy spurge. Because in one of my questions, when i chose a choice that had "that" modifier seperated from the noun by a non-vital modifier (as with choice B for the questions), i was marked wrong. So i rejected choice B for this question. I am kind of mis-guided.

Can you please help clarify the concept.

Thanks

egmat
I have a question. You wrote " The comma + verb-ing modifier displacing has been turned to simple present tense verb displaces. The comma + verb-ing modifier rendering correctly modifies the preceding action displaces, presenting the result of this action. Because the leafy spurge displaces grasses and other cattle food, it renders rangeland worthless. "
But I thought in correct ssentence "rendering" modifies its previous clause's two actions that are "gives mouth.. " and "displaces". However, from your sentence it seems to me that only "displaces" is the reason.So I feel confused. If two verb are jointed by and, will modifier only modify last verb?!

Posted from my mobile device

Thank you for your brilliant explanation. I have a few questions which I can use your help with. My questions are mainly about verb-ing modifier.
In the wrong answer choice A, you pointed out that both displacing and rendering would refer to the action, in the preceding clause, gives. That leads me wonder why we cannot do the same for the following sentence, for which your team has offered excellent explanation.

As a result of record low temperatures, the water pipes on the third floor froze, causing the heads of the sprinkler system to burst, then releasing torrents of water offices on the second floor.
My question here is that why releasing cannot modify the action, similarly in the preceding clause, to burst. Especially as you mentioned that

"Verb-ing modifiers
1. When separated by comma modifies the preceding clause
2. When not separated by comma modifiers the preceding noun or noun phrase
"

My question is that which action or part of the sentence or which action the verb-ing modifiers refer to?

Looking forward to your reply.

Best regards,
Li

Hi Shraddha,

Nice to read your answer. I also chose B because I have same logic with you, except the modifier " that gives mouth sores to cattle and displaces grasses and other cattle food". IMO, this modifier modifies for milky sap.

I don't understand why above modifier modifies for "leafy spurge". If we summarize the sentence, it should be "About 5 million acres in the United States have been invaded by leafy spurge with milky sap that gives mouth sores to cattle and displaces grasses and other cattle food, rendering...".

Please correct if I'm wrong. Thanks.

Full disclosure: I totally got punked by this one during our last verbal chat. Join us for the next one! https://gmatclub.com/forum/verbal-chat- ... 78-20.html I mean, it's fun to see a guy with an 800 get embarrassed, right?

As some others have pointed out, this one is all about the intersection of structure and meaning. (And there are already some excellent explanations here, but, well, I promised to write one as penance, so here you go.)


I really only notice two things in (A). "That gives mouth sores to cattle" seems to modify "milky sap", and I guess that's OK.

But then at the end of the sentence gives us a pair of parallel "-ing" modifiers, "displacing grasses... and rendering rangeland worthless." And what do they modify?

Hold that thought. We'll come back to that in a second.


OK, so the added commas around "with milky sap" change things just a tiny bit: "that gives mouth sores to cattle and displaces grasses..." now clearly modifies "a herbaceous plant from Eurasia." Hm, that makes a lot of sense.

And now "rendering" clearly modifies the preceding clause, "that gives mouth sores to cattle and displaces grasses and other cattle food." That also makes a lot of sense: rangeland is rendered useless by this evil plant that gives mouth sores to cattle and displaces their food sources.

Back to (A), then:

So wait: in (A), it's the milky sap that gives the mouth sores to cattle -- not the leafy spurge itself, as (B) would indicate. In that sense, (B) seems to be a slightly better choice. It's a bigger problem, presumably, if the entire plant gives mouth sores to cattle.

More importantly: "displacing grasses and rendering rangeland useless", would generally modify the preceding clause. And that's pretty illogical in (A): "that gives mouth sores to cattle" has absolutely nothing to do with "displacing grasses." And in that sense, (B) is much clearer.

So (A) is gone. And the rest are easier to eliminate:


Parallelism in (C) is clearly wrong: "... and displacing grasses" is parallel to what, exactly? "Having milky sap", I guess? That's a mess. We can comfortably eliminate (C).


I really don't love "having been invaded" in this case. In general, "having + verb" needs to be the first of two actions, and that's just not happening here. (For more on this topic, see our last chat transcript.)

Also, the parallelism at the end of the sentence isn't ideal: "... with milky sap that gives mouth sores to cattle, displaces grasses..., and renders rangeland worthless." The sap displaces grasses? That doesn't make sense. (D) is gone.


(E) is similar to (D): "having been" doesn't seem quite right, and "giving mouth sores to cattle" is parallel to "displacing grasses", suggesting that the milky sap displaces grasses -- and that doesn't make sense. (E) is gone, too, and (B) is our winner.

Hello hellosanthosh2k2,

I apologize for answering this question so late. But as they say better late than never,

The noun modifier that in the correct answer choice refers to a little far-away noun entity leafy spurge. Take a good look at the structure of Choice B. Whenever that is used to modify the immediate preceding noun entity, it is NEVER separated with that entity with a comma.

But in this choice, here is a comma between milky sap and that. Basically, both the modifiers - a herbaceous plant from Eurasia and with milky sap - are enclosed between commas because they just provide some additional information about the leafy spurge that are not crucial to core meaning of the sentence.

Hence, the noun modifier that jumps over the preceding modifiers and modify leafy spurge.

Please review our very famous article Noun Modifiers can Modify slightly far away noun to learn when noun modifiers can modify a slightly far-away nouns by clicking on the following link:
https://gmatclub.com/forum/noun-modifiers-can-modify-slightly-far-away-noun-135868.html

Hope this helps.
Thanks.
Shraddha

Hello rma26,


I apologize for answering this question so late. But as they say better late than never.

Per the rule, the comma + verb-ing modifier modifies the IMMEDIATE preceding action. So if there are two verbs associated with and, as we see in this official sentence, the comma + verb-ing modifier will modify the closest action.

This is the reason why in this official correct sentence, comma + rendering... modifies the closest action displaces.
Following correct official sentence is another example of the same usage:

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, traveling most rapidly through cold, dense regions and more slowly through hotter rocks.


Hope this helps.
Thanks.
Shraddha

This is perhaps the worst official GMAT SC question I have ever seen: the OA of B is still the best choice due to verb parallelism / meaning issues, but it is wordy and horribly punctuated.

Sometimes on the GMAT, the "best" choice is pretty darn far from the perfect version.

My perfect version: About 5 million acres in the United States have been invaded by leafy spurge, a herbaceous plant from Eurasia with milky sap, which gives mouth sores to cattle, displaces grasses and other cattle food, and renders rangeland worthless.

Also, in the 2018 OG the phrase "a herbaceous plant from Eurasia" is in italics in Choice B for some reason.

-Brian

AjiteshArun , GMATNinja , mikemcgarry , egmat , sayantanc2k, RonPurewal , DmitryFarber , MagooshExpert , ccooley , GMATNinjaTwo , mcelroytutoring , daagh , other experts -- please enlighten.

1.In OA - B , that modifies a herbaceous plant from Eurasia or leafy spurge? I understand that CAN'T refer to "with milky sap" since its enclosed between commas.

2. The below is the perfect version stated by mcelroytutoring -
About 5 million acres in the United States have been invaded by leafy spurge, a herbaceous plant from Eurasia with milky sap, which gives mouth sores to cattle, displaces grasses and other cattle food, and renders rangeland worthless.
Is the parallelism here okay?

3. In OA- B, the verb-ing modifier rendering modifies the preceding verb displaces or both the verbs gives and displaces that are parallel ?
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 and displaces grasses and other cattle food, rendering rangeland worthless

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.

if i remove this bold underlined part considering it as non essential modifer,then sentence will read as:

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

So i am stuck here:

the result of action of invasion is displacing and redering so makes sense.

Now displacing and rendering should make sense with the doer of the action "have been invaded"

so who is doer in this case?

Subject is 5 million acres but doer as pe rme is leafy sponge bcz it does action of invasion but doer is subject .Right?

So if doer is 5 million acres,then rendering dioesnot make sense but if doer is leafy sponge ,it does.So can u please clear me how to find doer?

And if i write sentence as:

Leafy spurge have invaded about 5 million acres in the United States , displacing grasses and other cattle food and rendering rangeland worthless.

This is correct?

bcz subject/doer is leafy sponge and it is displacing and rendering.Right?

Please clarify my doubt of doer in original sentence.

And yes i read in one of doubt clarification posts,

comm+verbing modifies nearest verb so modies gives here.Is it a rule?

Full disclosure: I totally got punked by this one during our last verbal chat. Join us for the next one! https://gmatclub.com/forum/verbal-chat- ... 78-20.html I mean, it's fun to see a guy with an 800 get embarrassed, right?

As some others have pointed out, this one is all about the intersection of structure and meaning. (And there are already some excellent explanations here, but, well, I promised to write one as penance, so here you go.)


I really only notice two things in (A). "That gives mouth sores to cattle" seems to modify "milky sap", and I guess that's OK.

But then at the end of the sentence gives us a pair of parallel "-ing" modifiers, "displacing grasses... and rendering rangeland worthless." And what do they modify?

Hold that thought. We'll come back to that in a second.


OK, so the added commas around "with milky sap" change things just a tiny bit: "that gives mouth sores to cattle and displaces grasses..." now clearly modifies "a herbaceous plant from Eurasia." Hm, that makes a lot of sense.

And now "rendering" clearly modifies the preceding clause, "that gives mouth sores to cattle and displaces grasses and other cattle food." That also makes a lot of sense: rangeland is rendered useless by this evil plant that gives mouth sores to cattle and displaces their food sources.

Back to (A), then:

So wait: in (A), it's the milky sap that gives the mouth sores to cattle -- not the leafy spurge itself, as (B) would indicate. In that sense, (B) seems to be a slightly better choice. It's a bigger problem, presumably, if the entire plant gives mouth sores to cattle.

More importantly: "displacing grasses and rendering rangeland useless", would generally modify the preceding clause. And that's pretty illogical in (A): "that gives mouth sores to cattle" has absolutely nothing to do with "displacing grasses." And in that sense, (B) is much clearer.

So (A) is gone. And the rest are easier to eliminate:


Parallelism in (C) is clearly wrong: "... and displacing grasses" is parallel to what, exactly? "Having milky sap", I guess? That's a mess. We can comfortably eliminate (C).


I really don't love "having been invaded" in this case. In general, "having + verb" needs to be the first of two actions, and that's just not happening here. (For more on this topic, see our last chat transcript.)

Also, the parallelism at the end of the sentence isn't ideal: "... with milky sap that gives mouth sores to cattle, displaces grasses..., and renders rangeland worthless." The sap displaces grasses? That doesn't make sense. (D) is gone.


(E) is similar to (D): "having been" doesn't seem quite right, and "giving mouth sores to cattle" is parallel to "displacing grasses", suggesting that the milky sap displaces grasses -- and that doesn't make sense. (E) is gone, too, and (B) is our winner.

In the original sentence with milky sap tends to modify Eurasia, Can we say this?

Hiee , can anyone explain

In the correct ans B.

how we can use displaces as the verb to grasses ?

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Correct answer B in the sentence
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 and displaces grasses and other cattle food, rendering rangeland worthless.