Displays of aurora borealis

[poonamchiK]

[Moderator's Note: This is a wrongly copied version of a GMAT Prep problem. See below for the correct version and explanation]

Displays of aurora borealis, or "northern lights," can heat the atmosphere over the arctic enough to affect the trajectories of ballistic missiles, induce electric currents that can cause blackouts in some areas and corrosion in northsouth pipelines.
(A) to affect the trajectories of ballistic missiles, induce

(B) so as to affect the trajectories of ballistic missiles inducing

(C) such that the trajectories of ballistic missiles are affected, and induced are

(D) to affect the trajectories of ballistic missiles, and induce

(E) to affect the trajectories of ballistic missiles, which induce.

I found this one particularly triky and got mixed up in the correct and the wrong ans. Chose the wrong one instead.

OA : D .
I chose an E. I got mixed up in the meaning. I didnt know whether A.B induced electric currents or whether ballistic missiles led to tht.

Pls help and mk me understand

[jnelson0612]

Again, we need an original source for this question before we can respond.

[poonamchiK]

From ETS, a division of MLIC (Maple leaf)...
I got this content from a friend who has attended their course.
its from one of the 25 mins practice set questions.

thx!
P

[RonPurewal]

this question looks like a VERY incorrectly transcribed version of #70 in og11. the prompt is pretty much exactly the same, but the answer choices are ... weird.
and the "correct" answer isn't quite right, either.

since this problem is apparently someone's (inferior) attempt to steal an OG question, we'll leave it alone.

[gmat.acer]

This question is from GMATPrep default question pack. Please see the image:



http://postimage.org/image/sxps22oz9
Since this question appears in gmatprep and not just in OG, I believe we can continue this thread. If we cannot, please let me know and I will delete my post.

Displays of the aurora borealis, or "northern lights," can heat the atmosphere over the arctic enough to affect the trajectories of ballistic missiles, induce electric currents that can cause blackouts in some areas and corrosion in north-south pipelines.

(A) to affect the trajectories of ballistic missiles, induce
(B) that the trajectories of ballistic missiles are affected, induce
(C) that it affects the trajectories of ballistic missiles, induces
(D) that the trajectories of ballistic missiles are affected and induces
(E) to affect the trajectories of ballistic missiles and induce

From the correct choice (E), I understand that "induce" is parallel
to "affect". While solving this question I was debating over the intended parallelism of "induce" - is it intended to be parallel with "affect" or "heat".
Were there a comma before 'and' in (E), would "induce" be parallel with "heat"? A comma would add a logical pause after the first long clause - Displays .. can heat...to affect ... missiles.

Displays ..... can heat ... enough to affect the trajectories of ballistic missiles, and induce ... pipelines.

in terms of basic structure above sentence can be seen as:
Displays .. can
heat X
, and induce Y

[jlucero]

You've got it exactly right. Commas between two parallel elements are there to ensure parallelism with an element further away in the sentence.

[ericyuan0811]

hello instructors

can we eliminate (D) because the subject of "affect" and "induce"
changes to "trajectories" rather than the intended "displays of the aurora borealis"?

thanks for your help!

[jlucero]

hello instructors

can we eliminate (D) because the subject of "affect" and "induce"
changes to "trajectories" rather than the intended "displays of the aurora borealis"?

thanks for your help!

affect is ok- it's fine to say "displays affect the trajectories" or displays are so X that trajectories are affected" (although the idiom in D is not the same as what I have here and is wrong)

induce is wrong because it isn't parallel with anything in the sentence, so to your ear, it may sound like it's talking about something else in the sentence. Ultimately it's wrong because the subject is unclear.

[DianaT513]

Part of the explanation in the GMAT software says that the correct idiom form is can heat...enough to affect; that. I don't understand why "enough" goes with "that" and why "that" has a semi-colon.

Thank you for your help!!!

[RonPurewal]

Part of the explanation in the GMAT software says that the correct idiom form is can heat...enough to affect; that. I don't understand why "enough" goes with "that" and why "that" has a semi-colon.

Thank you for your help!!!

can you give a more complete citation?

if i had to bet $5, i'd bet that they're actually saying that "enough to affect..." is the idiom, and that "that" is part of whatever they're saying next.
remember how semicolons work (unless they're used to demarcate a list): the stuff before the semicolon should be a sentence, and the stuff after it should be another sentence.

[RonPurewal]

in any case, there's no need to appeal to idioms. instead, you can just realize that 'enough' + 'so'/'such' is wrong, because it's redundant.

Sally is tall enough to see over the fence.
Sally is so tall that she can see over the fence.
^^ note that 'enough' (in the former sentence) and 'so' (in the latter) are doing essentially the same thing.**
so, the inclusion of both would create redundancy.

--

(**)
THIS FOOTNOTE IS COMPLETELY IRRELEVANT TO THE GMAT

there's a difference of degree/emphasis.
specifically, the second sentence implies that the fence is tall and that, therefore, sally is WHOA SO TALL that she can actually see over the (already quite tall) fence.
the first, on the other hand, carries no such implication; it can be used to speak about a fence of any height at all (maybe sally is just a kid growing at a normal rate). if the fence IS super-duper-tall, then most native speakers would not say the first sentence; instead, they'd say something more like the second.

again, THIS FOOTNOTE IS COMPLETELY IRRELEVANT TO THE GMAT; it is here only for your edification and/or enjoyment.

[vishalc581]

Hi Ron,

I am still not able to figure out induce is parallel to heat or affect.

Further, can you please explain the below point you mentioned:

"Commas between two parallel elements are there to ensure parallelism with an element further away in the sentence."


Thanks & Regards,
Vishal

[RonPurewal]

Hi Ron,

I am still not able to figure out induce is parallel to heat or affect.

heat... and induce...

you can figure this out, because heat doesn't spontaneously create electric currents.

but, even if not, you don't actually have to figure this out. in this problem it's sufficient to realize that 'induce' is parallel to ONE of those things. ironically, there is no need to figure out which, since both are written in the same form.

this is most likely intentional, by the way—if it were absolutely necessary to make this decision, you'd be given a problem with a much more obvious distinction between sense and nonsense.

[RonPurewal]

Further, can you please explain the below point you mentioned:

"Commas between two parallel elements are there to ensure parallelism with an element further away in the sentence."

joe wrote that; i'm not sure whether he posts on the forum anymore (i haven't seen anything from him in a while).

...but this has no importance either way, because the presence/absence of punctuation is not tested on this exam. you will NEVER have to deal with 'comma present vs. comma absent'.

[vishalc581]

Hi Ron,

I still didn't get the parallelism part.

If induce were intended to be parallel with can heat, then the sentence would read as follows:

Displays CAN HEAT the atmosphere over the arctic enough to affect the trajectories of ballistic missiles and CAN INDUCE electric currents.

am I right?

Thanks & Regards,
Vishal