Changes in the composition of the light of a supernova—an exploding

Question

Changes in the composition of the light of a supernova—an exploding star— reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas .

(A) reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas

(B) reveals not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding

(C) not only reveal the chemical elements in the explosion but also the speed of the expanding outer layers of stellar gas

(D) not only reveal what chemical elements are in the explosion but also the speed of the outer layers of stellar gas when they are expanding

(E) reveal not only the chemical elements in the explosion but also the speed at which the outer layers of stellar gas are expanding

daagh · Accepted Answer

There is no need to gallop to solve this entry-level question if you are thorough with some SAT level grammar

Step 1. Eliminate A and B since the plural subject 'changes' does not synchronize with the singular verb 'reveals'

Step 2. All the three of them use the correlative conjunction not only… but also. The thumb rule of correlative conjunction parallelism is that what is on the right side of not only should also be there on the right side of but also, in letter and spirit

In C and D, "not only" is followed by the verb -reveal- while 'but also' is followed by a noun.

Only E puts a noun after both "not only" … "but also."

leeye84 · Answer

I had C on my first try. I understand the S-V agreement, but how is the parallelism in place here?

Swagatalakshmi · Answer

(E) 

Reveal not only A but also B is the correct form.

In other choices ||ism is broken by saying "Not only reveal A but also <needed>"

pmshah007 · Answer

I think the options B, C and D breaks the parallelism rule. Not only X but also Y, X and Y should be parallel. A and E both have parallel X and Y but they A is incorrect due to its faulty S-V agreement (Changes .... reveals), Hence I picked E
Pls correct me if I am wrong
PS

jrk23 · Answer

I was confused with subject here, not sure whether it was "Changes" or "an exploding star".

Subject will not be in prep phrase.

In this example on what grounds we decide that "an exploding star" is not a subject.

Thanks in advance for the help.

Rgds,
Ram

GMATCoachBen · Answer

Hi  jrk23 ,

Here are 3 ways to decide:

1) Punctuation

A pair of dashes is similar to parentheses, or 2 commas. " - an exploding star -" just serves to define what a supernova is.

You are correct that "Subject will not be in prep phrase".

"in the composition of the light of a supernova - an exploding star -" is a common tactic by the test writers to distract you from the subject, "Changes"

For subject-verb issues, ignore modifiers such as this and simplify it to "Changes reveal".

2) Structure

If "reveals" is the verb for "an exploding star", then "Changes" would be hanging without a verb. A common error is to have no main verb for a subject.

3) Meaning

"Changes reveal" fits better with the intended meaning.

Is it the star ITSELF that reveals the chemical elements in the explosion and speed of expanding the outer layers?

Or is it the changes in the composition of light?

atrayee345 · Answer

Subject in this sentence is “Changes” which is in plural form. So, it doesn’t get along with singular “reveals”. Hence, A and B are out. In answer choice C, “speed of expansion” should replace “speed of expanding”. “not only” is used wrongly in Choice D. It should follow “reveal”. “not only” preceding “reveal” means it is just not only revealing but also doing something else. E has correct Subject-verb agreement and the use of adverb. Hence, E is the answer

meenakshimiyer · Answer

Subject in this sentence is “Changes” which is in plural form. So, it doesn’t get along with singular “reveals”. Hence, A and B are out. In answer choice C, “speed of expansion” should replace “speed of expanding”. “not only” is used wrongly in Choice D. It should follow “reveal”. “not only” preceding “reveal” means it is just not only revealing but also doing something else. E has correct Subject-verb agreement and the use of adverb. Hence, E is the answer.

hiranmay · Answer

Changes  in the composition of the light of a supernova--an exploding star--  reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas .

(A)  reveals  not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas —> “changes” is plural, so “reveals” is wrong

(B)  reveals  not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding —> same as A

(C) not only  reveal  the chemical elements in the explosion but also  the speed  of the expanding outer layers of stellar gas —> wrong: not only “reveal” ... but also “the speed”

(D) not only  reveal  what chemical elements are in the explosion but also  the speed  of the outer layers of stellar gas when they are expanding—> wrong: not only “reveal” ... but also “the speed”

(E) reveal not only  the chemical elements  in the explosion but also  the speed  at which the outer layers of stellar gas are expanding—>  correct : not only “the elements” ... but also “the speed”

dabaobao · Answer

Main Issues:  
1) Correct Idiom: "Not only X but also Y"
2) Subject Verb agreement

(A)  reveals  not only the chemical elements in the explosion but also the speed of  expanding the outer  layers of stellar gas  - Wrong: SV 2) Meaning distortion

(B)  reveals  not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding  - Wrong: SV

(C) not only reveal the chemical elements in the explosion  but also the speed  of the expanding outer layers of stellar gas  - Wrong: Parallelism issue

(D) not only reveal what chemical elements are in the explosion  but also the speed  of the outer layers of stellar gas  when  they are expanding  - Wrong: Parallelism issue 2) Meaning distortion

(E) reveal not only the chemical elements in the explosion but also the speed at which the outer layers of stellar gas are expanding  - Correct

schooliscool · Answer

Changes is plural
Reveals is plural form. Why is everyone saying reveals is singular form? i am very confused by that.

EducationAisle · Answer

Hi  schooliscool , that's the funny thing about English: For the most part,  Nouns  are  plural  when they end in "s" while  Verbs  are  singular  when when they end in "s".

Since  reveals  is a  verb  that ends in "s",  reveals  is  singular  ( reveal  would be  plural ).

throwaway2353 · Answer

I narrowed it down to C and E quickly.

I chose C because I thought "are expanding" was wrong. Wouldn't just "expand" make more sense? I understand the //ism error in C now, but I don't understand how "Are expanding" is ok. Any help on this would be very appreciated!

Jr2000wharton · Answer

Big boss, thanks for your replies!

Changes in the composition of the light of a supernova—an exploding

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