The spectacular disintegration of a comet last year in full view of gr

I agree with daagh that the use of "and" here necessitates a verb in the first part of the sentence. Notice that there is no verb at all in the non-underlined portion, so you need a verb in the underlined portion. But the underlined portion says "A and thus B"--so A and B need to be parallel, and they must both contain verbs. As daagh says, that knocks off B, C, and D.

I also agree that the meaning shifts in E, but I have a different (grammatical) reason for losing E. There is a verb split between A and E-- "provided" versus "has provided." What might help us distinguish which of these options is incorrect? Both sentences use the phrase "last year," but you cannot use the present perfect tense (has/have + past participle) if you name the specific point in the past when that action happened.

Last year, I ate 10 pizzas. CORRECT
Last year, I have eaten 10 pizzas. INCORRECT

In 1998, I owned twenty pairs of shoes. CORRECT
In 1998, I have owned twenty pairs of shoes. INCORRECT

One thing to be careful of when applying this rule is the word "since"--"since 1998" means...in the period of time between 1998 and leading up to the present," so you *can* use a specific date with "since" and the present perfect.

Since 1998, I have been to Paris four times. CORRECT
In 1998, I went to Paris four times. CORRECT (but different meaning)
In 1988, I have gone to Paris four times. INCORRECT.

E incorrectly uses the present perfect, so A is our answer.

Note:
(1) "and" is a very important PARALLEL marker. Two parts before and after "and" must be parallel.
(2) Verb+ed modifier always modifies preceding NOUN


The spectacular disintegration of a comet last year in full view of ground- and space-based telescopes provided new insights into how comets form and thus may force a rethinking of the role of comets in the delivery of organic compounds to the evolving earth.

A. The spectacular disintegration of a comet last year in full view of ground- and space-based telescopes provided new insights into how comets form and thus may force
Correct. Good structure: X provided.... and thus may force......

B. The spectacular disintegration of a comet last year in full view of ground- and space-based telescopes, provided new insights into how comets form and thus possibly forcing
Wrong. Modifier problem. Verb+ed modifier always modifies preceding NOUN. "provided" modifies "telescopes" <-- wrong.

C. When a comet's spectacular disintegration occured in full view of ground- and space-based telescopes last year, it provided new insights into how comets form and thus possibly forcing
Wrong. Parallelism problem. Past tens vs. Verb-ing modifier

D. Last year, in full view of ground- and space-based telescopes, a comet's spectacular disintegration provided new insights into how comets form and thus possibly forcing
Wrong. Parallelism problem. Past tens vs. Verb-ing modifier

E. Last year, in full view of ground- and space-based telescopes, the spectacular disintegration of a comet has provided new insights into how comets form and may thus force
Wrong. Tense problem. Present perfect never goes with "Last year".

Hope it helps.

Dear Friends,

Here is a detailed explanation to this question-



Choice A: Option A maintains parallelism and proper tense usage throughout the sentence and conveys the intended meaning. Thus, Option A is correct.

Choice B: In Option B, "provided..." incorrectly modifies "telescopes" rather than "disintegration". Thus, Option B is incorrect.

Choice C: In Option C, we see a parallelism error between "provided" and "forcing" as the former is a verb and the latter is a modifier. Remember, elements joined by "and" must be parallel. Thus, Option C is incorrect.

Choice D: Option D repeats the parallelism error found in Option C. Thus, Option D is incorrect.

Choice E: Option E uses the wrong tense, present perfect, in the phrase "has provided" to refer to something that concluded in the past; this is evidenced by the use of the phrase "Last Year".

Hence, A is the best answer choice.

To understand the concept of “Present Perfect Tense on GMAT”, you may want to watch the following video (~1 minute):



All the best!
Experts' Global Team
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nothing wrong with A here.

B: as well as is wordier than "and" and is not needed here. and thus possibly forcing is awkward and could be better said as: and may thus force.
C: "it" has no clear referent.
D: thus possibly forcing is incorrect.
E: again as well as is wordier than and

Also I think some of the meaning is lost when you change around the sentence as done in D and E.

(A) The spectacular disintegration of a comet last year in full view of ground- and space-based telescopes provided new insights into how comets form and may thus force
(B) The spectacular disintegration of a comet last year in full view of ground- as well as space-based telescopes, provided new insights into how comets form and thus possibly forcing
(C) When a comet's spectacular disintegration occurred in full view of ground- and space-based telescopes last year, it provided new insights into how comets form and thus may possibly force
(D) Last year, in full view of ground- and space-based telescopes, a comet's spectacular disintegration provided new insights into how comets form and thus possibly forcing
(E) Last year, in full view of ground- as well as space-based telescopes, the spectacular disintegration of a comet has provided new insights into how comets form and may thus force

A.
That was tricky.
@kaijen: I think that E changes the meaning of the sentence. You could understand that the disintigration of the comet provided insights in the last year. This does not mean that the disintigration took place the last year.

Don't forget to check not only the grammar but also the meaning and sense of the sentence.

I think I deserve kudos

A for me too. I was stuck between A and E.
I rejected E on two grounds: the use of commas which makes the second phrase a non-essestial modifier which is not the case here. The phrase " in full view of ground- as well as space-based telescopes" is essential to meaning of the sentence, so the use of commas is not justified. Secondly, the use of perfect tense is not necessary. The action has already occured and simply requires a present tense. The infromation derived from that action may be present but the action is already over. Also, you do not need a present perfect when you are talking about a specific point of time in the past that has already occured.

If you can remember two basic things in the given context, the answer will pop up.

1. The co-ordinate conjunction - and – joins two equal things and so if you have a clause on one side of the -and - you must necessarily have another clause on the other side. Otherwise the sentence is un-parallel. So B and D are out for using the incomplete phrase thus possibly forcing after the co-ordinate conjunction – and-

2. The disintegration occurred last year. The adverb last year must not be far removed from the disintegration.

The misplacement of the adverb -last year- after - telescopes in C and - before in full view of ground - in E, fouls this structural rule.


Then we are left only with A.

The point is that in a pressure-cooker test such as GMAT, if you can spot at least one error in a choice, then dump it and get going than pull your hair on fine prints. Any takers?
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A clause joined by the coordinating conjunction is required to have a full working verb, which, choices B, C and D are lacking, by using the incorrect present participial, 'thus forcing"

In E, the time of the disintegration i.e. last year has been placed far distant from the disintegration. We cannot separate last year and disintegration as that choice ends up with a wrong word order.

A is the choice, IMO
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It is A. E is wrong because it suggests that disintegration has provided insights in full view of telescopes. Tricky.

Hi all,
Can someone guide me over the difference between "provided" and " , provided" in option A and option B?
Thanks

In Option B

, provided new insights into how comets.... is acting a modifier for the first part of the sentence.

However if we look closely than the first part below has no verb and hence a sentence fragment.
"The spectacular disintegration of a comet last year in full view of ground- as well as space-based telescopes"

parker :- the "it" in Option choice is correct, right??
Because there is only one singular noun it can refer to, so "it" is correct?

Am assuming you are talking about option C.

it in C refers to comet's spectacular disintegration.
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A and thus B. Both A and B must be parallel.

So the sentence must read- comets form and thus may force. B, C and D are out.

In E 'has' indicates that comet provided something and still is providing. It is not the intended meaning. Disintegration provided something in the past. E is out.

A is the answer
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A is the right option here, correct tenses, no modifier problems and, and no parallelism issues. C and D have parallelism problems, past tense does not fit with the ‘ing’ verb form. E uses the present perfect tense, which is incorrect when talking about something that happened a definite amount of time in the past. In B, provided is modifying telescopes, when it should be modifying ‘disintegration…’

AjiteshArun Please explain why option E is wrong. And can we use has in option E?

Hi Bishal123456789,

We can't use the present perfect (has provided) for something in the past if the time has been specified.

1. He has done his homework. ← This is fine.
2, Yesterday evening, he has done his homework. ← Adding the yesterday evening makes this sentence incorrect.

3. Last year, the spectacular disintegration of a comet has provided new insights ← Wrong, for the same reason.

We can also take option E out on the basis of a meaning call:

A. The spectacular disintegration of a comet last year... ← This makes it quite clear that it was the disintegration that happened last year.

E. Last year, in full view of ground- as well as space-based telescopes, the spectacular disintegration of a comet has provided new insights... ← Option E does not connect last year to disintegration. Instead, it seems to suggest that (i) even though we don't know when the disintegration happened, the disintegration provided insights last year and (ii) the providing of insights happened "in full view of ground- as well as space-based telescopes".

What we want to say is (i) that the disintegration happened last year and (ii) that the disintegration happened "in full view of ground- as well as space-based telescopes".
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There are many splits in this question. First, parallelism between provided and force. So, remove all forcing questions. Eliminate B and D.

C is wrong on two accounts may and possibly is redundant and it changes the meaning by using when.

Now, between A and E, difference between as well as & and - in "and", we have equal weight age of verbs. Then has provided and provided-usage of "Last year" and "has provided" cant be together. So, A is correct.