Hei,

I have a general doubt for the experts. How do hypehns work on a sentence. Are they like a coma, or like a semi-colon or what?

And also, in this question I didnt know how to choose between A and C. Luckilly I choose correctly but can anyone explain why?

Thanks

Luci, answer choice C awkward and wordy. By beginning with when, this choice implies that the time of the comet's disintegration was the most pertinent factor for scientists, rather than the disintegration itself. Choice C is also redundant by stating may possibly force. Since possibly simply means may, there is no reason to use both words. Conversely, choice A clearly uses the more standard and clear Subject - Verb - Object (The disintegration provided new insights) sentence structure.

As for your question about hyphens, they are used to connect words that directly relate to one another. For non-native English speakers, this might seem somewhat confusing, especially since English contains a nearly identical punctuation mark - the dash - that is used to provided emphasis or clarification. Fortunately, the GMAT is not a test of punctuation and thus will never base a correct answer choice on one of these grammatical structures.

Hope that helps.
-dan

Dan,

Hypothetically, if there were no "comma" between telescope and provided in asnwer choice B, which one would be better answer choice.

A) The Spectacular disintegration ...................................................................and may thus force

b) The Spectacular disintegration ...................................................................and thus possibly forcing

i am not sure but i'll try.

we can't use "as well as" with plural verb telescopes.
"as well as" does not compound the subjects and make them plural as "and" does.

ex: The player as well his team members is going to the party.

can someone please clear this doubt.

mridul12, the first option is still better, as is contains a proper subject-verb-object structure (The disintegration may force a rethinking). In essence, the second option says The disintegration possibly forcing a rethinking. Once simplified to this level it becomes more obvious that a provable verb error exists.

-dan

Whats wrong with E.. ???? :cry:

One major issue with E is that it combines the present perfect tense "has provided" with a definite point in time "last year."

The present perfect tense can serve a couple of functions. First, it can express an action that started in the past and runs into the present.
An example: I have lived in San Francisco for 10 years.

Another function is to express an action in the past at an indefinite point in time.
Example: I have traveled widely through Africa.


Choice E uses the tense along with "last year" with an odd result. Consider saying "I have lived in San Francisco two years ago."

Rey