Twenty-two feet long and 10 feet in diameter, the AM-1 is on

[gmatkiller_24]

[redacted]

[RonPurewal]

essentially no difference.

[RonPurewal]

.

[RonPurewal]

.

[RonPurewal]

also consider:

• 'an effort to ___' vs. 'an effort that has ___'

if you're describing the goal/purpose of the 'effort'—as in this sentence—then you should use the first of these, since 'to ___' is specifically used for goals/purposes.

the second of these doesn't express the idea that '___' is actually THE POINT OF the effort. in actual praxis, in fact, this latter construction is just as likely to describe results that diverge from the original purpose.
e.g.,
The government's effort to outlaw Drug X had the unintended effect of making Drug X more popular.
--> THE POINT of the 'effort' was to outlaw the drug.
--> however, its actual effect was quite different.

[RonPurewal]

finally,
'for xxxx years' can describe only an action, not a noun. (i.e., 'an effort for 15 years' is not idiomatic.)

[VikrantS137]

I have read through the posts above, but still not clear why D is wrong. Can you please elaborate?

[RonPurewal]

it's explained in the post directly above yours:

'for xxxx years' can describe only an action, not a noun.

e.g.,
Jack lived in Bangkok for 15 years.
(correct sentence)
here 'for 15 years' is describing the action (Jack lived in Bangkok). that is the only thing it's allowed to do.

if we apply this here, we must read choice D as
... are part of an effort for 15 years...
this doesn't make sense, because 'are' makes no sense with a time period.

we cannot read 'for 15 years' as a modifier of 'effort', because 'for [time period]' doesn't describe nouns.

[RonPurewal]

incidentally, even if you can't pinpoint exactly what's wrong with D, you can still eliminate it on the grounds that it's clearly inferior to some of the other choices.

consider:
Individuals who engage in athletic pursuits are advised to perform stretching exercises
vs.
Athletes should stretch

the latter of these is clearly better than the former. (this should be super-obvious here, as i've exaggerated the difference as much as possible.)

the difference between D and the other choices isn't as massive as the difference between these two, but it's still readily perceptible.

this is a trend in SC in general, by the way:
if it's particularly hard to EXPLAIN what's wrong with a choice... it will usually be easier to recognize that it's concretely WORSE THAN OTHER choices.

in other words, when absolute judgments are harder, relative judgments will be easier. this way the exam is a substantive test of both skill sets.

[NikhilS427]

The OE is that...

[RonPurewal]

if there's an official explanation, then that means this is one of the paid questions. that means we can't host it here, so, this thread is now locked.