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

HI GMATNinja
I eliminated C for the reason that noun modifier 'having' is incorrectly modifying Eurasia....Am I wrong here?
Further, I eliminated choice B because I thought the use of noun modifier THAT is incorrect (to add more, it is using ,that). I should I not get confused in these kinds of situations. Cause I was following the rules I learnt about modifiers.
Thank You!

egmat

Kindly can you be explicit as possilbe here because it seems like there's disagreement in the thread with some of the other experts.

Does the comma + -ing modifier only modify the closest action "displaces..." or because of the 'and' parallel marker does it modify the entire thing "That gives...and displaces..." ? It would seem incorrect to say the later is correct because we agreed that in answer A, the action of giving mouth sores has nothing to do with rending the land useless.

in option B , how are we allowed to place that after a comma ?
This is an error in most other examples

Hello sevenplusplus,

I would be glad to help you resolve your doubt.

Let's take a look at the original 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, displacing grasses and other cattle food and rendering rangeland worthless.

(Blue = subject, Green = verb, Pink = comma + verb-ing modifiers)

Let's understand what the sentence intends to convey. The sentence states that in the US, some 5 million acres of land have been invaded leafy spurge. Describing the leafy spurge, the sentence states that it's a plant from Eurasia. It has milky sap that gives mouth sores to cattle. This leafy spurge displaces grasses and other cattle food and renders rangeland worthless.

However, the way this sentence is worded, it suggests that because leafy spurge gives mouth sores to cattle, it displaces grasses and other cattle food and has rendered rangeland worthless.

We get this illogical meaning from the sentence because of the incorrect usage of the comma + verb-ing modifiers* displacing and rendering.

The comma + verb-ing modifier must modify the preceding action logically and must also make sense with the doer of the modified action.

In this official sentence, the comma + verb-ing modifiers displacing and rendering illogically modifies the preceding action gives by presenting the result of this action. Grasses and other cattle food are not displaced and rangeland are not rendered worthless because leafy spurge gives mouth sores to cattle.

This is the reason why Choice A is incorrect.

From the context of the sentence, we can understand that because leafy spurge displaces grasses and other cattle food, rangeland are rendered useless. So we do have this logical cause-and-effect in the sentence that must be communicated in correct grammar.

Let's evaluate Choice B now:

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.

This choice correctly conveys the logical intended meaning. 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.

*The correct usage of comma + verb-ing has been covered in great details and with pertinent examples in our SC course, In fact, this concept features in the Free Trail course offered by e-GMAT. You can register for free at e-gmat.com and review the concept.


Hope this helps.
Thanks.
Shraddha

@AndrewN- Just to confirm if I have understood this question correctly, request you to please let me know if my below summary is correct.

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.

"displacing grasses and other cattle food and rendering rangeland worthless" can refer to any of the following nouns:
1. sap
2. leafy spurge
3. 5 million acres

Option A is wrong because the above modifying phrase can refer to any of these three nouns (that is all three of them make sense meaning-wise)> Hence, there's a clear ambiguity in concluding the actual referent. Eliminate Option A.

In Option B, it is clear that the referent is "leafy spurge" (and of course there are no structural/grammatical errors)- Hence our answer is B.

I would be glad to help you resolve your doubt.

Let's take a look at the original 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, displacing grasses and other cattle food and rendering rangeland worthless.

(Blue = subject, Green = verb, Pink = comma + verb-ing modifiers)

Let's understand what the sentence intends to convey. The sentence states that in the US, some 5 million acres of land have been invaded leafy spurge. Describing the leafy spurge, the sentence states that it's a plant from Eurasia. It has milky sap that gives mouth sores to cattle. This leafy spurge displaces grasses and other cattle food and renders rangeland worthless.

However, the way this sentence is worded, it suggests that because leafy spurge gives mouth sores to cattle, it displaces grasses and other cattle food and has rendered rangeland worthless.

We get this illogical meaning from the sentence because of the incorrect usage of the comma + verb-ing modifiers* displacing and rendering.

The comma + verb-ing modifier must modify the preceding action logically and must also make sense with the doer of the modified action.

In this official sentence, the comma + verb-ing modifiers displacing and rendering illogically modifies the preceding action gives by presenting the result of this action. Grasses and other cattle food are not displaced and rangeland are not rendered worthless because leafy spurge gives mouth sores to cattle.

This is the reason why Choice A is incorrect.

From the context of the sentence, we can understand that because leafy spurge displaces grasses and other cattle food, rangeland are rendered useless. So we do have this logical cause-and-effect in the sentence that must be communicated in correct grammar.

Let's evaluate Choice B now:

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.

This choice correctly conveys the logical intended meaning. 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.

*The correct usage of comma + verb-ing has been covered in great details and with pertinent examples in our SC course, In fact, this concept features in the Free Trail course offered by e-GMAT. You can register for free at e-gmat.com and review the concept.


Hope this helps.
Thanks.
Shraddha

Hi egmat

My analysis of the sentence, in addition to yours, is:
a herbaceous plant ... is additional information
And displacing does not make sense with the subject 5 million acres in United States. That is why displacing is not the correct verbing modifier to be used here.

Is this analysis correct?
Or else(without this analysis) how can we say that displacing could not have modified the main clause of the sentence?

GMATNinja


In your post you use the word 'seems' to say the word 'that' modifies milky sap. Is that because the word 'that' can reach over two prepositional modifiers and touch back to the plant? so one reading would result in a logical meaning with the -ing modifier and in an illogical meaning?

Hello sevenplusplus,

I would be glad to help you resolve your doubt.

Let's take a look at the original 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, displacing grasses and other cattle food and rendering rangeland worthless.

(Blue = subject, Green = verb, Pink = comma + verb-ing modifiers)

Let's understand what the sentence intends to convey. The sentence states that in the US, some 5 million acres of land have been invaded leafy spurge. Describing the leafy spurge, the sentence states that it's a plant from Eurasia. It has milky sap that gives mouth sores to cattle. This leafy spurge displaces grasses and other cattle food and renders rangeland worthless.

However, the way this sentence is worded, it suggests that because leafy spurge gives mouth sores to cattle, it displaces grasses and other cattle food and has rendered rangeland worthless.

We get this illogical meaning from the sentence because of the incorrect usage of the comma + verb-ing modifiers* displacing and rendering.

The comma + verb-ing modifier must modify the preceding action logically and must also make sense with the doer of the modified action.

In this official sentence, the comma + verb-ing modifiers displacing and rendering illogically modifies the preceding action gives by presenting the result of this action. Grasses and other cattle food are not displaced and rangeland are not rendered worthless because leafy spurge gives mouth sores to cattle.

This is the reason why Choice A is incorrect.

From the context of the sentence, we can understand that because leafy spurge displaces grasses and other cattle food, rangeland are rendered useless. So we do have this logical cause-and-effect in the sentence that must be communicated in correct grammar.

Let's evaluate Choice B now:

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.

This choice correctly conveys the logical intended meaning. 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.

*The correct usage of comma + verb-ing has been covered in great details and with pertinent examples in our SC course, In fact, this concept features in the Free Trail course offered by e-GMAT. You can register for free at e-gmat.com and review the concept.


Hope this helps.
Thanks.
Shraddha

The comma + verb-ing modifier must modify the preceding action logically and must also make sense with the doer of the modified action.

My question is do the verb-ing modifiers also modify the action of the preceding clause even if that clause is dependent as with option A

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? :-D

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.

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? :-D

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.