Carbon monoxide levels in the atmosphere grew by enough of an increase

Question

Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.

A) Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.

B) Carbon monoxide levels in the atmosphere increased by enough of a percentage during the twentieth century that they began to trap heat radiating from the Earth, causing the average surface temperature to rise.

C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.

D) Atmospheric carbon monoxide levels increased by a sufficient percentage during the twentieth century to begin trapping heat radiating from the Earth, which caused the average surface temperature to rise.

E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.

daagh · Accepted Answer

Yes. Almost all of the choices are ugly. Burt amidst this awkwardness let us fish out some grammar

A) Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise. ---- - grew and increased are redundant. In addition it refers to what? Carbon monoxide, or atmosphere, or percentage? Terrible pronoun ambiguity.

B) Carbon monoxide levels in the atmosphere increased by enough of a percentage during the twentieth century that they began to trap heat radiating from the Earth, causing the average surface temperature to rise.  - -‘increased by enough ……….that they began to trap’ is not idiomatic.’

C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.  – Correct sentence using the present participle causing, which rightly modifies the entire noun idea before.

D) Atmospheric carbon monoxide levels increased by a sufficient percentage during the twentieth century to begin trapping heat radiating from the Earth, which caused the average surface temperature to rise. ----- ‘ Which’ - flouts relative pronoun touch rule

E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise. ---  The wrong placement of the phrase ‘during the twentieth century, after ‘the atmosphere’ distorts the meaning of the sentence, ending to mean as if the cause of the effect was.

BillyZ · Answer

Official answer from Manhattan Prep.

The original sentence contains several errors. First, " grew by enough of an increased percentage " is wordy and redundant. Second, the singular pronoun " it " incorrectly refers to the plural " levels ." Finally, the final clause of the sentence--"and it caused the average surface temperature to rise"--is disjointed from the main clause.

(A) This choice is incorrect as it repeats the original sentence.

(B) This choice uses the unnecessarily wordy phrase " increased by enough of a percentage ."

(C) CORRECT.  The sentence is made more concise by rewriting " grew by enough of an increased percentage " as " increased sufficiently ." This choice also eliminates the pronoun "it" from the sentence and reworks the final clause--"causing the average surface temperature to rise"--as a modifier, thereby more clearly connecting it to the main clause.

(D) This choice uses the unnecessarily wordy phrase "increased by a sufficient percentage." It also uses "which" to refer to the action of the preceding clause, though "which" grammatically refers only to the immediately preceding noun (in this case, "Earth").

(E) This choice alters the position of "during the twentieth century", thereby changing the meaning of the sentence. In this choice "during the twentieth century" modifies the carbon monoxide levels instead of describing when those levels "increased." This distorts the meaning by leaving open the possibility that carbon monoxide levels "increased enough" during some other time period (e.g., the 21st century).

aaron22197 · Answer

OA is C. But I really do not see any difference between C and E. Can anyone explain y not E?

C and E use the exact same words. Only the placement of "during the 20th century" is different

spider · Answer

The word increased is placed closer to what its modifying in C - the CO levels. In E its placed closer to 20th century....

Hence C

GMAT TIGER · Answer

C.

A.  grew by enough of an increased percentage  is an awakward expression
B.  increased by enough of a percentage  is an awakward expression
C.   increased sufficiently  
D.  increased by a sufficient percentage  is an awakward expression
E.  increased enough to begin  is an awakward expression

judokan · Answer

A) Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.
>> "grew by enough of an increased percentage" is awkward.

B) Carbon monoxide levels in the atmosphere increased by enough of a percentage during the twentieth century that they began to trap heat radiating from the Earth, causing the average surface temperature to rise.
>> "grew by enough of an increased percentage" is awkward.

C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.
== Correct

D) Atmospheric carbon monoxide levels increased by a sufficient percentage during the twentieth century to begin trapping heat radiating from the Earth, which caused the average surface temperature to rise.
 >> modifier "during the twentieth century" in wrong position

E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise. 
 >> modifier "during the twentieth century" in wrong position

sleepynut · Answer

Hi,
I agree that option C is the best of all.But doesn't "increased sufficiently...to begin" sound strange?
It seems the intention of such increase is to begin something.

Thanks

BillyZ · Answer

You may refer the picture screenshot from Advanced Cambridge dictionary.

utkbits · Answer

To me none of the options look correct. In option C, it seems like the level of the gas increased purposefully to do begin trapping heat. I have seen lot of questions where "to" is used to show purpose.

AKY13 · Answer

I don't see any of the options standing strong in the meaning. 
"The levels of CO" didn't begin trapping heat
"The CO at increased level" began trapping heat

lynlyn · Answer

Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.

A) Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise. -  "it" refers to? no antecedent

B) Carbon monoxide levels in the atmosphere increased by enough of a percentage during the twentieth century that they began to trap heat radiating from the Earth, causing the average surface temperature to rise. -  "they" refers to? only plural noun is "levels", which does not trap heat...

C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise. -  correct

D) Atmospheric carbon monoxide levels increased by a sufficient percentage during the twentieth century to begin trapping heat radiating from the Earth, which caused the average surface temperature to rise. -  "which" modifies "the Earth" and the earth does not cause the temperature to rise

E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise. -  "during the twenties century" should modify increase, but here it is modifying atmosphere

David nguyen · Answer

Hi could you please explain (E) in another word? I am still confused by the placement of "during the 20th century". How does it distort the meaning of the sentence.

MGMAT explanation: This choice alters the position of "during the twentieth century", thereby changing the meaning of the sentence. In this choice "during the twentieth century" modifies the carbon monoxide levels instead of describing when those levels "increased." This distorts the meaning by leaving open the possibility that carbon monoxide levels "increased enough" during some other time period (e.g., the 21st century).

What I don't understand is that how does it leave open the possibility that CO levels "increased enough" during some other time period. How "Levels of carbon monoxide in the atmosphere during the twentieth century increased enough" could leave the possibility in another period? It does not make any sense to me.

Please advise. I really appreciate it.

iamdivs · Answer

daagh hazelnut I have the same question. We would appreciate if you could explain through an example if possible

Posted from my mobile device

Kritisood · Answer

daagh

is "they" a reason to eliminate B?
as per me it correctly refers back to the plural subject.

aw2112 · Answer

Comparing C and E - C is also more concise with the earlier phrase 'Levels of atmospheric carbon monoxide' rather than 'Levels of carbon monoxide in the atmosphere'

NischalP · Answer

daagh  Sir,

In C D E options to begin ( Infinitive ) is used.
when we replace "to begin" with "in order to" the options don't convey the meaning.
How to proceed in such cases.

TarPhi · Answer

Doesn't it seem in Answer C that the levels of Carbon Monoxide and not the Carbon Monoxide itself is "trapping heat radiating from the Earth, causing the average surface temperature to rise"?

Abhi077   generis   hazelnut

draftpunk · Answer

In answer choice C, is "to begin" used appropriately?

I thought this irregular verb is used to show intent, which 'levels' are incapable of showing.

CrackverbalGMAT · Answer

This question has a mix of modifier, pronoun and idiomatic usage errors.

In Option A, there is the idiomatic error “grew by enough of an increased percentage”. The verb ‘grew’ should ideally not be used with the noun 'level'. The verb ‘increase’ is better in this sentence. 
Option A also has a pronoun error. The singular pronoun ‘it’ has been used to refer to the plural antecedent ‘levels’.

Option B corrects the idiomatic error in Option A, but is also wrong because it has a bulky, wordy expression – “by enough of a percentage”.

Option D also has an error of pronouns. The relative pronoun ‘which’ has been placed immediately after “the Earth”, implying that ‘the Earth’ caused the average surface temperature to rise. A relative pronoun takes the word immediately preceding it as its antecedent.

In this sentence, the phrase ‘during the twentieth century’ acts as a modifier to give us a timeline for the increase in the levels of atmospheric carbon monoxide. If the modifier is placed immediately after the phrase “Levels of carbon monoxide in the atmosphere”, it modifies this phrase instead, thereby conveying the meaning that the levels of carbon monoxide under discussion are restricted to the twentieth century. The modifier describes the noun ‘levels’ rather than the verb ‘increase’. Therefore, Option E is incorrect.

In Option C, the phrase ‘increased sufficiently’ is idiomatically correct. The modifier also has been placed correctly in this option. C is the most appropriate option.

Jayanthi Kumar.

Carbon monoxide levels in the atmosphere grew by enough of an increase

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Carbon monoxide levels in the atmosphere grew by enough of an increase

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