RaviChandra wrote:
Until Antoine Lavoisier proved otherwise in the eighteenth century,
many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood.
a) many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood
b) many scientists believed that phlogiston was an imaginary substance released by combustion and its properties were not fully understood
c) phlogiston was an imaginary substance whose properties were not fully understood and which many scientists had believed was released by combustion
d) phlogiston, an imaginary substance whose properties were not fully understood, was believed by scientists to be released by combustion
e) many scientists had believed that phlogiston was released by combustion and was an imaginary substance whose properties were not fully understood
MGMAT suggests "if the two actions are sequenced properly in the sentence, it is not necessary to use past perfect tense"..
in the sentence Until X proved, scientists had believed. Clearly suggests that " scientists believing was the first action" & Antoine proving is the action that followed it"
So do we really need "Had" in the Correct Answer Or is the answer still stands grammatically correct even after removing "had from it"
My suggestion for your question.
Simple past vs Past perfect.We use
Simple Past if we give past events
in the order in which they occured. However, when we
look back from a certain time in the past to tell what had happened before, we use
Past Perfect.In this question, clearly
we do not talk about sequence of events. However, we use the point - Until Antoine Lavoisier proved otherwise - which happened in the past to
look back other action (in the past) happened before it. Clearly, past perfect is correct.
ANALYZE THE QUESTION:
Until Antoine Lavoisier proved otherwise in the eighteenth century,
many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood.
a) many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood
Correct. Past perfect + active voice --> good grammar.
b) many scientists believed that phlogiston was an imaginary substance released by combustion and
its properties were not fully understood
Wrong. "its" refers to "combustion" or "substance" --> ambiguous.
c) phlogiston was an imaginary substance whose properties were not fully understood and which many scientists had believed
was released by combustionWrong. Passive voice "was released..." is not necessary.
d) phlogiston, an imaginary substance whose properties were not fully understood,
was believed by scientists to be released by combustion
Wrong. "believed by X to be Y" --> not preferable in GMAT. (refer idiom chapter in
MGMAT - sentence correction - page 150).
e) many scientists had believed that phlogiston
was released by combustion and was an imaginary substance whose properties were not fully understood
Wrong. Between A and E, A is better by using active voice. E, however, uses passive voice.
Hope it helps.