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by ankur.agrawal » Tue Mar 22, 2011 1:07 am
In the 18th century, Antoine Lavoisier demonstrated that combustion consumes oxygen; previously, many scientists had believed that combustion released phlogiston, an imaginary substance that was believed to extinguish flames.


consumes oxygen; previously, many scientists had believed that combustion released phlogiston, an imaginary substance that was believed to extinguish flames

consumed oxygen, and many scientists had previously believed that phlogiston was an imaginary substance released by combustion, which extinguished flames

consumes oxygen; phlogiston was previously an imaginary substance that was believed to extinguish flames and that many scientists had believed was released by combustion

consumed oxygen; phlogiston, an imaginary substance that extinguished flames, was believed by scientists to be released by combustion

consumes oxygen; previously, many scientists had believed that phlogiston was released by combustion and was an imaginary substance that was believed to extinguish flames.

OA after some discussion.
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by gmatmachoman » Tue Mar 22, 2011 1:16 am
IMO A.

E looks close but alters the intended meaning.

Original sentence properly uses past perfect to show the sequence of events ( had believed....... &....... demonstrated)
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by HSPA » Tue Mar 22, 2011 1:27 am
+1 for A

combustion consumes oxygen is one pack of words.. so please ignore consumed

E) phlogiston was released "during" combustion; lengthy.. phlogiston or i guess CO2 was released and was an imaginary substance

what is the right word to go with combustion... is it during combustion or in combustion???
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by AIM GMAT » Tue Mar 22, 2011 1:52 am
IMO A.

consumes oxygen; previously, many scientists had believed that combustion released phlogiston, an imaginary substance that was believed to extinguish flames

consumed oxygen, and many scientists had previously believed that phlogiston was an imaginary substance released by combustion, which extinguished flames --- wrong use of which

consumes oxygen; phlogiston was previously an imaginary substance that was believed to extinguish flames and that many scientists had believed was released by combustion --- changes meaning + non parallel structure

consumed oxygen; phlogiston, an imaginary substance that extinguished flames, was believed by scientists to be released by combustion --- passive

consumes oxygen; previously, many scientists had believed that phlogiston was released by combustion and was an imaginary substance that was believed to extinguish flames. --- changes meaning
Thanks & Regards,
AIM GMAT
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by gmat_perfect » Tue Mar 22, 2011 5:06 am
ankur.agrawal wrote:In the 18th century, Antoine Lavoisier demonstrated that combustion consumes oxygen; previously, many scientists had believed that combustion released phlogiston, an imaginary substance that was believed to extinguish flames.


consumes oxygen; previously, many scientists had believed that combustion released phlogiston, an imaginary substance that was believed to extinguish flames

consumed oxygen, and many scientists had previously believed that phlogiston was an imaginary substance released by combustion, which extinguished flames

consumes oxygen; phlogiston was previously an imaginary substance that was believed to extinguish flames and that many scientists had believed was released by combustion

consumed oxygen; phlogiston, an imaginary substance that extinguished flames, was believed by scientists to be released by combustion

consumes oxygen; previously, many scientists had believed that phlogiston was released by combustion and was an imaginary substance that was believed to extinguish flames.

OA after some discussion.
C,D,and E can easily be eliminated.

B, which has wrongly used "which", is wrong for changing the intended meaning of the sentence.

.........combustion, which extinguish flames... it means that "combustion extinguish flames". Combustion is the process of burning. Can a process of burning extinguish flames. Nope.

Answer is thus A.
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by ankur.agrawal » Tue Mar 22, 2011 8:09 am
OA is A.

Thanks everybody.
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by gmat1978 » Mon Jul 18, 2011 6:41 pm
I have a couple of questions about the past perfect tense used in answer choice A. Why do we need the past perfect to clarify the sequence of events (believed and demonstrated)? In this case, doesn't the use of "Previously" clearly state that "believed" happened before "demonstrated"? Don't we use past perfect only if it is necessary to clarify the sequence? Please help.

Many thanks.
gmatmachoman wrote:IMO A.

E looks close but alters the intended meaning.

Original sentence properly uses past perfect to show the sequence of events ( had believed....... &....... demonstrated)
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