Bunuel wrote:
Bunuel wrote:
Scientists are currently trying to determine the extent to which tectonic plates have been shifted from their previous positions by earthquakes and other similar phenomena.
(A) to which tectonic plates have been shifted
(B) to which tectonic plates have shifted
(C) of the shift of tectonic places
(D) of tectonic plate shifting
(E) that tectonic plates have been shifted
KAPLAN OFFICIAL EXPLANATION:
Start with verb options: should the verb be have been shifted or have shifted? Normally one would want to avoid the passive have been shifted, but here it's necessary because the rest of the sentence tells you what did the shifting, i.e., the earthquakes. Therefore, the plates "have been shifted...by earthquakes"; eliminate (B). You can also eliminate (C) because of the shift...by earthquakes is incomplete without a verb. (E) is unidiomatic because that shouldn't follow extent. (D) makes no sense in the context of the sentence, so (A) stands.
Bunuel,
WOuld you pls elaborate more about option C why its incorrect.
From my prospective, in this sentence "Scientists are currently trying to determine" is followed by two things and those two are joined by "and". And it should be parallel.
In Option A & B in presence of "have" verb they act as clause whereas 2nd entity is a phrase, and it is in non-underline part. SO to maintain parallelism 1st entity should also be a phrase rather than a clause.
Pls suggest.