mmslf75 wrote:Ron,
Sentence from OG 12
A 1972 agreement between Canada and the United States reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes.
A.
B.reduced the phosphate amount that municipalities had been dumping
C.reduces the phosphate amount municipalities have been allowed to dump
D.reduced the amount of phosphates that municipalities are allowed to dump
E.reduces the amount of phosphates allowed for dumping by municipalities
Dont understand why D is the answer here !!
A looks good as well, !?
Disclaimer : I am not questioning the GMAT official answers - it's unproductive , but would like to learn a new takeaway if any ;-)
there are actually two acceptable constructions here:
were and
are. the former isn't a choice, so the latter wins.
here's an attempt at explanation:
IF YOU WERE TO WRITE THIS SENTENCE IN THE PRESENT TENSE, you'd get
the new agreement reduces the amount that municipalities are allowed to dump..
you wouldn't say "have been" in this situation, because the previous, continuous nature of the action
is not important in context.
therefore, if you translate this into the past tense, it can't be "had been", either, for the same reason. (if the sentence works with "had been" in a past context, it should also work with "has been" in a present context.)
by contrast,
the new rule bans the social-networking sites on which the school's students have been wasting their time during library hours.
note that:
* the behavior up until this point is crucial to the meaning this time, AND
* the students
can't waste their time on these sites anymore. since the new rule
curtails this activity, the present perfect ("up to the present") is especially appropriate.
if you translate this one into the past, you get
the new rule banned the social-networking istes on which the school's students had been wasting their time during library hours.
--
as usual, i'm going to close this discussion with the caveat that Verb Tenses Are Really Really Really Complicated. they are EASILY the most complicated, subtle aspect of ANY language.
if you are not a native speaker of english, then verb tenses are probably the worst possible topic of study, especially in rather esoteric cases like this one.
