Astronomers at the Palomar Observatory have discovered a distant super

Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that they believe is a type previously unknown to science.
(A) that they believe is
one already works as pronoun, use of that is not required.
Preposition 'of' is required before 'type'
'believe to be' is idiomatic
(B) that they believe it to be
Similar to A
'it' is redundant
(C) they believe that it is of
'believe to be' is idiomatic
(D) they believe that is
'believe that is' unidiomatic
Missing the require Preposition 'of'
(E) they believe to be of
Correct removal of the duplicate pronoun 'that'
'believe to be' is idiomatic
Preposition 'of' is correctly used

A lot of folks are incorrectly stating that "that" is incorrect or redundant after "one." While there are certainly forms that allow us to skip "that," it's not incorrect here. We can say "one that they believe" or "one that they believe," depending on whether our meaning seems clear enough without the "that." "One" is a pronoun here, but it works just the way a noun does, and we can modify it the way we'd modify any noun.

A few examples:

I shared a poem that I believed was masterfully written. (Here, "that" helps to make it immediately clear that I believed something about the poem, rather than that I believed the poem itself. This is a common reason to include "that" or "who/whom.")
I shared several poems, including one that I believed was masterfully written.
I met many people that day, but there was one person I couldn't forget. ("That," or better yet, "whom," wouldn't be wrong here, but the meaning is 100% clear as is.)
Sitting across from me was a person I had believed to be dead.
Sitting across from me was a person whom I had believed was dead. (This second version feels clunkier. Although the "whom" makes it clear that I will be describing my belief, rather than saying I believed the person, the meaning was already fairly clear in the first version. I think some of the awkwardness comes from the switch from past perfect--had believed--to simple past--was. Although this switch is correct, it creates more work for the reader than the previous version, with its time-independent use of "to be.")
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105. Anger: singular
D: not parallel.

B is best

145

Idiom: believe to be.
Do not need THAT following ONE.

E is best.

9. Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that they believe is a type previously unknown to science.
(A) that they believe is : is creating a run on sentence
(B) that they believe it to be : "it" redundant, no need to have since the phrase is talking about the "one = explosion"
(C) they believe that it is of : wordy
(D) they believe that is : wordy
(E) they believe to be of : concise, correct

I assumed the following construction (which called 'absolute phrase') for the second sentence.

one ( xxxx, describing explosion ) of a type previously unknown to science.
( xxxx = they believe to be ) -> 'that' sometimes to be omitted ex) I ran to the office (that) I like.

please correct my reasoning if wrong.

To clarify the doubt on inverted sentence as mentioned earlier

----" Among a group of things " one thing is asked making it singular
-----This is an inverted subject-verb sentence. Reverse it: "Anger was among the emotions on display..."

i have checked this question from 1000 SC #107 .... Here in non-underlined part as mentioned below "were" is used with "high cost of land" ....
I feel it is the same case as mentioned earlier.
Correct me if i m missing smthing

107. Among the reasons for the decline of New England agriculture in the last three decades were the high cost of land, the pressure of housing and commercial development, and basing a marketing and distribution system on importing produce from Florida and California.

Amit

Hi Kassim .The first three options here are starting with that...if u read the full sentence it reads thus "Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that........" ...so if u scrutinize keenly u can see that the pronoun ONE has " distant supernova explosion " as an antecedent...again pronoun "that" also leads to the same antecedent ..so presence of two pronouns for the same noun phrase makes the construction absolutely redundant...so u can immediately strike A, B and C ..now " believe to be " is a perfectly acceptable idiom ..so E is the right option ....

Refer this question :
a-recent-study-on-lyme-disease-suggests-that-people-who-are-169777.html

A recent study on Lyme Disease suggests that people who are bitten by ticks, especially by the lone star tick, develop a severe allergy to meat that scientists believe to be turning into an epidemic
a.to be
b.would be
c.is
d.it is
e.it would be

and then refer:
the-world-wildlife-fund-has-declared-that-global-warming-a-103470.html

Compared to these two questions I am not able to understand why option E is correct in this question.

Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that they believe is a type previously unknown to science.

(A) that they believe is [DSE is a type... nope. It's not type;it's of type]
(B) that they believe it to be [explosion is already referred by "one" so "it" not req. IMO there is no ambiguity in it usage. ]
(C) they believe that it is of
(D) they believe that is
(E) they believe to be of

"one" refers to the explosion, and the explosion is not a type, it is "of" a type. A-B and D cannot be the answer.
C is wrong because "believe that" phrase breaks the relationship of "one" and "believe"
E is the only option without a mistake.

I would take a different approach to this question

<A Singular thing> can be OF a TYPE
<A Singular thing> CANNOT be A TYPE

Hence, only valid options are C and E. C is clearly wrong as IT does not have an antecedent.
ANS E

Regards

since astronomers have discovered a supernova... the belief has to be singular right?

daagh GMATNinja

The noun "belief" never appears in this sentence at all, so there's no reason to worry about whether it's singular or plural. The word "believe" is a verb here, and it's "performed" by the plural noun "astronomers" -- and that's why all five answer choices include "they believe", with both the subject and verb in the plural form. And since the same exact construction appears in all five answer choices, it's a non-issue, anyway.

I hope this helps!
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“Believe + to be” is the correct usage. Hence, A and D can be eliminated.
B and C can be eliminated for the unnecessary use of ‘it’.
E is the best choice

Option E is correct answer. 'believe to be' is idiomatic and Preposition 'of' is correctly used in Option E.

One is already acting as a pronoun hence we don't need the second "that" in few options & it is reduntant in few options.

Option E is the best answer.
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Main Issues:

1) Parallelism: "explosion" = "of type" and not "type"
2) Redundancy: No need for a pronoun right after a pronoun (i.e. "one that")
3) Redundancy: "it" when "one" is already in use


Not an Issue: Both idiom "believe to be" and "believe that" are correct.

(A) that they believe is - Wrong: Issue 1 & Issue 2 ("one that")
(B) that they believe it to be - Wrong: Issue 1, Issue 2 & Issue 3
(C) they believe that it is of - Wrong: Issue 3
(D) they believe that is - Wrong: Issue 1
(E) they believe to be of - Correct

IN NY TIMES use (-) but test maker change it to comma !!! comma in here is problem and I don't know because with hyphen it can refer to previous noun (explosion) !!! and comma make make run on sentence ! everybody can help me ? i go for answer B ..... noun +that !
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For starters, the GMAT very rarely tests the fine points of punctuation. More on that in this video.

In this particular case, we don't actually have a run-on sentence at all: the part after the comma is just a noun that's used to describe the "distant supernova explosion" in more detail. There is nothing wrong with using a comma to separate extra information about the noun before the comma, so (E) is perfectly acceptable.

You'll find numerous correct GMAT answer choices that use commas to separate additional (non-essential) information. Such sentences often look something like this: "The scientists created a monster, one capable of destroying entire civilizations." The phrase "one capable of destroying entire civilizations" is just a noun that modifies "a monster."

For trickier examples from the GMAT Prep software, check out this one from the GMATPrep exams or this one from the GMATPrep question pack. There's also a similar GMAT Club test question here.

I hope this helps!
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in your example "The scientists created a monster, one capable of destroying entire civilizations." it did not use verb !!!!! all is noun.... but in this case ".....,one they believe to be of " we have verb ! this is my problem ! if it is modifier after comma why we use verb "believe" ???


I think : """Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one {that} they believe to be of a type previously unknown to science.""""" and "that" is omitted and plausible. it can be infer it is true .
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"they believe" can be used in 2 pattern

I have a pen that , they believe, is good

I have a pen that they believe to be good

the above patterns come from

they believe those students are good
they believe those students to be good.


in both patterns, "that" can be omitted.

both patterns in choice A and E are correct. but choice A is wrong because of meaning problem. explosion can not be a type, but belong to a type.