Most efforts to combat such mosquito-borne diseases like malaria and

Question

Most efforts to combat such mosquito-borne diseases  like malaria and dengue have focused either on the vaccination of humans or on exterminating  mosquitoes with pesticides.

(A) like malaria and dengue have focused either on the vaccination of humans or on exterminating

(B) like malaria and dengue have focused either on vaccinating of humans or on the extermination of

(C) as malaria and dengue have focused on either vaccinating humans or on exterminating

(D) as malaria and dengue have focused on either vaccinating of humans or on extermination of

(E) as malaria and dengue have focused on either vaccinating humans or exterminating

The Official Guide for GMAT Review 2017

Practice Question  
Question No.: SC 796
Page: 708

PurpleDrank3000 · Answer

“either on the vaccination of humans or on exterminating”

Is this parallel? Both “either” and “or” have prep phrases that start with “on”. Or is this not parallel because “vaccination” doesn’t match “exterminating”?

“either on vaccinating of humans or on the extermination of”

Same question as I put above. Both the X and Y elements here start with the preposition “on”. Is “on” alone enough to make these elements parallel? Do the “vaccinating” and “extermination” portions of the X and Y element matter?

egmat · Answer

Hello PurpleDrank3000 , You certainly ask a good question here.

However, there are certain considerations here. Firstly, vaccinating of humans is an incorrect expression. We can say vaccinating humans or vaccination of humans . Similarly, we can use extermination of mosquitoes or exterminating mosquitoes in the context of this sentence. So let's work with these expressions. As long as the sentence uses either X or Y, either on vaccinating humans or on the extermination of mosquitoes AND/OR either on vaccination of humans or on exterminating mosquitoes will be parallel because ultimately both either and or are followed by prepositional phrases. But suppose if this sentence only uses the parallel marker or and not either X or Y , then in that case neither vaccinating humans can be parallel to the extermination of mosquitoes nor vaccination of humans will be parallel to exterminating mosquitoes . The verb-ing noun forms cannot be parallel to a conventional noun. The reason for the same is that verb-ing nouns denote action while the conventional nouns denote a person, a place, or a thing. Coming back to the official sentence, we see that the correct answer choice uses perfect parallelism even after the preposition on because a parallel list must be as much parallel as possible. If the two expressions can be written in identical form, then they must be written so. Hope this helps.

Thanks. Shraddha

sanpreetsingh · Answer

A. like malaria and dengue have focused either on the vaccination of humans or on exterminating

B. like malaria and dengue have focused either on vaccinating of humans or on the extermination of

C. as malaria and dengue have focused on either vaccinating humans or on exterminating

D. as malaria and dengue have focused on either vaccinating of humans or on extermination of

E. as malaria and dengue have focused on either vaccinating humans or exterminating

A,B - "like" to present examples
C,D - parallelism issue on either .. or on...
The correct parallelism would have been ...on either or....
either on... or on....

Hence, E is the Answer.

EMPOWERgmatVerbal · Answer

Hello Everyone!

Let's tackle this question, one issue at a time, and narrow it down to the right answer quickly! To start, let's take a quick look at the original question and highlight any major differences between the options in  orange :

Most efforts to combat such mosquito-borne diseases  like malaria and dengue have focused either on the vaccination of humans or on exterminating  mosquitoes with pesticides.

A.  like  malaria and dengue have focused  either on  the vaccination of humans or  on exterminating 
B.  like  malaria and dengue have focused  either on  vaccinating of humans or  on the extermination of 
C.  as  malaria and dengue have focused  on either  vaccinating humans or  on exterminating 
D.  as  malaria and dengue have focused  on either  vaccinating of humans or  on extermination of 
E.  as  malaria and dengue have focused  on either  vaccinating humans or  exterminating

After a quick glance over the options, a few key differences jump out:

1. like vs. as ( Idioms )
2. either on vs. on either ( Parallelism & Idioms )
3. on exterminating / on the extermination of / on extermination of / exterminating ( Parallelism )

Let's start with #1 on our list because it will knock out 2-3 options right away.  This is an issue of idioms! In English, it's actually incorrect to introduce examples with the word "like." We use the word "like" in similes to show how to things are alike - not that they are examples of a larger category. To introduce examples, we use "as" or "such as." Here are some examples:

To save money, consider shopping at discount store  like  thrift shops and consignment stores. -->  WRONG 
To save money, consider shopping at discount stores,  such as  thrift shops and consignment stores. -->  CORRECT

The air smelled  like  fresh dew. --> CORRECT 
The air smelled  as  fresh dew. --->  WRONG

So let's see how our options hold up:

A.  like  malaria and dengue have focused either on the vaccination of humans or on exterminating
B.  like  malaria and dengue have focused either on vaccinating of humans or on the extermination of
C.  as  malaria and dengue have focused on either vaccinating humans or on exterminating
D.  as  malaria and dengue have focused on either vaccinating of humans or on extermination of
E.  as  malaria and dengue have focused on either vaccinating humans or exterminating

We can eliminate options A & B  because they don't use the correct idiom structure to introduce examples. That was a quick way to eliminate 2 options, right?

Now that we've narrowed things down a bit, let's tackle #2 & #3 on our list.  They actually have to do with the same grammar concept:  parallelism !

We need to make sure that the two items that are being focused on are written using parallel structure:

C. as malaria and dengue have focused  on either  vaccinating humans or  on  exterminating

have focused on either X or on Y  =  NOT PARALLEL

D. as malaria and dengue have focused  on either  vaccinat ing  of humans or  on  extermina tion  of

have focused on either X or on Y  =  NOT PARALLEL 
 (This is also incorrect because the two items don't use the same wording: vaccinating & extermination)
 
E. as malaria and dengue have focused on  either vaccinating  humans or  exterminating

have focused on either X or Y  =  PARALLEL

There you have it - option E is the correct choice!  It's the only one that uses the proper idiom "as" to introduce examples, and it uses parallel structure when listing the two items being focused on.

Don't study for the GMAT. Train for it.

swatihod123 · Answer

the correct answer is E

as malaria and dengue have focused on either vaccinating humans or exterminating- such as is idiomatic. Correct parallel structure (either vaccinating or exterminating)

mzaid · Answer

I got the parallelism thing here, but in option E, doesn't pesticide could means vaccinating humans too which is illogical.

rahul12988 · Answer

(A) apart from like , either X or Y parallelism is wrong 
X= on vaccination & Y = on exterminating 
(B)Like, either X or Y parallelism & vaccinating of humans
(C) either X or Y
(D) either X or Y
(E) correct

VIGHNESHKAMATH · Answer

Hello,

I have a question. Can gerund be considered parallel to a proper noun phrase, as in Option B? I have heard that GMAT doesn't like to compare Gerund with a pure noun. I have seen one example when gerund was turned to a pure noun by using an article before it, in order to maintain the parallelism. Is there any absolute rule on this?

Please guide.

Regards
Vighnesh

ExpertsGlobal5 · Answer

Hello  VIGHNESHKAMATH ,

We hope this finds you well.

To answer your query, one of the functions of the present participle is to serve as a noun; in these cases, the present participle can grammatically parallel any given noun; typically, present participles that serve as nouns are, indeed, marked by articles: for example, "A killing was reported last night.", "The drawing of the lots will take place tomorrow."

We hope this helps.
All the best!
Experts' Global Team

VIGHNESHKAMATH · Answer

There seems some confusion. I thought in above sentence, vaccinating and exterminating are acting as a gerund, not a present participle.

ExpertsGlobal5 · Answer

There seems some confusion. I thought in above sentence, vaccinating and exterminating are acting as a gerund, not a present participle.

Hello  VIGHNESHKAMATH ,

We hope this finds you well.

To clarify, gerunds can parallel any other type of noun - for example, "Savings are as important as investments.": here, the gerund "Savings" is parallel to the noun "investments".

However, in Option B "vaccinating" is a present participle, not a gerund, and in the correct answer choice - Option E - "vaccinating" and "exterminating" are both present participles, as well.

We hope this helps.
All the best!
Experts' Global Team

Elite097 · Answer

@expertsglobal5 how do we know vaccinating is a present participle not gerund and what can it be // to in that case

Hello  VIGHNESHKAMATH ,

We hope this finds you well.

To clarify, gerunds can parallel any other type of noun - for example, "Savings are as important as investments.": here, the gerund "Savings" is parallel to the noun "investments".

However, in Option B "vaccinating" is a present participle, not a gerund, and in the correct answer choice - Option E - "vaccinating" and "exterminating" are both present participles, as well.

We hope this helps.
All the best!
Experts' Global Team

glan2023 · Answer

The official explaination for option-B and option-D says:
"This use of gerund vaccinating would normally be preceded by  the  but this would make the phrase awkward.
Why would placement of "the" before complex gerund "vaccinating of humans" make the gerund phrase awkward?
 egmat  ,  GMATNinja ,  KarishmaB

ExpertsGlobal5 · Answer

Hello  glan2023 ,

We hope this finds you well.

To answer your query, the inclusion of "the" is likely considered awkward simply because it is unnecessary; even without "the", the answer choices lose no clarity.

We hope this helps.
All the best!
Experts' Global Team

KarishmaB · Answer

Note the use of 'such' in the non-underlined part. So we should use 'as,' not 'like.' Eliminate (A) and (B).
For parallelism, the structure of X and Y should be parallel in 'Either X or Y.'

(A) like malaria and dengue have focused either  on the vaccination of humans  or  on exterminating mosquitoes 
'vaccination' is a noun while 'exterminating mosquitoes' is a gerund phrase.

(B) like malaria and dengue have focused either  on vaccinating of humans  or  on the extermination of mosquitoes 
'vaccinating of humans' is a gerund phrase while 'extermination' is a noun.

(C) as malaria and dengue have focused on either  vaccinating humans  or  on exterminating mosquitoes 
'on' is used before 'either' so it is common to both X and Y. We should not use 'on' again in Y.

(D) as malaria and dengue have focused on either  vaccinating of humans  or  on extermination of 
'on' is used before 'either' so it is common to both X and Y. We should not use 'on' again in Y.
Also 'vaccinating of humans' is a gerund phrase while 'extermination' is a noun. Let's look for a better option.

(E) as malaria and dengue have focused on either  vaccinating humans  or  exterminating mosquitoes 
Both gerund phrases and perfect parallelism.

Answer (E)

KarishmaB · Answer

Official explanations are sometimes a bit iffy. Don't worry too much about them.

egmat · Answer

Hey  glan2023

Thank you for the query.

There are two things to understand here.

1. Why 'the' needs to be placed in B and D?
2. Why would placing 'the' make these sentences awkward?

1. The gerundial phrase in choices B and D is "vaccinating of humans". Note that gerundial phrases of the form " Gerund + prepositional phrase " are generally preceded by ' the '; whereas gerundial phrases of the form " Gerund + Object Noun " are  not preceded by 'the' . This is because when we use the phrase ' of something ' after a noun, that preceding noun automatically becomes specific to that thing it belongs to (the father of the bride; the champion of the people; etc.). However, when we say "vaccinating people", we're already referring directly to an action, which is unique in itself.

This is why we can make the following observations:

a. Cackling of geese is annoying. (Incorrect)
b. The cackling of geese is annoying. (Correct) 
c. Killing mosquitoes is strangely satisfying. (Correct)
d. The killing mosquitoes is strangely satisfying. (Incorrect)
e. The killing of mosquitoes is strangely satisfying. ( Awkward )

So, when the official explanation says that choices B and D would require 'the' before 'vaccinating', it is actually correct.

2. Coming to the second question, "why would adding 'the' make choices B and D awkward?". Well, that's because the phrase 'the vaccinating of humans' is ambiguous in meaning. Allow me to explain with one of the previous examples:

The cackling of geese is annoying.

Who is doing of the "cackling"? Is "geese" the doer of 'cackling' or the sufferer? Here, it is clearly the doer.

But, when we say, "the vaccinating of humans", are humans  being vaccinated  or are they  doing the vaccinating ?

So, think of the intended meaning. We wish to say "humans are being vaccinated". Hence, wouldn't it better to just use the phrase " vaccinating humans " than the ambiguous and awkward phrase "the vaccinating of humans"? This is exactly why example 'e' above is also awkward.

I hope you see why it's so important to choose our grammatical constructs carefully and wisely. Everything is connected to " MEANING ". So, work hard on improving your meaning analysis.

Hope this helps.

Happy Learning!

Abhishek

Deep32470 · Answer

Most efforts to combat such mosquito-borne diseases like malaria and dengue have focused either on the vaccination of humans or on exterminating mosquitoes with pesticides.

(A) like malaria and dengue have focused either on the vaccination of humans or on exterminating

(B) like malaria and dengue have focused either on vaccinating of humans or on the extermination of

(C) as malaria and dengue have focused on either vaccinating humans or on exterminating

(D) as malaria and dengue have focused on either vaccinating of humans or on extermination of

(E) as malaria and dengue have focused on either vaccinating humans or exterminating

In the above question if one is confused whether to use 'like' or 'as' even if knows well their usage, see the sentence

Most efforts to combat such mosquito-borne diseases- such is generally followed by as

NotFine233 · Answer

This is an older question, but helpful to get brain going in the morning. Thank you!

Posted from my mobile device

GmatKnightTutor · Answer

SUCH X as Y

Memorizing certain idioms can be helpful for GMAT SC. For anyone unfamiliar with the one above, consider searching for/checking out some idiom lists on the forum.

Most efforts to combat such mosquito-borne diseases like malaria and

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Most efforts to combat such mosquito-borne diseases like malaria and

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