Q. 29
The greatest road system built in the Americas prior to the arrival of Christopher
Columbus was the Incan highway, which, over 2,500 miles long and extending from
northern Ecuador through Peru to Southern Chile.

A. Columbus was the Incan highway, which, over 2,500 miles long and extending
B. Columbus was the Incan highway, over 2,500 miles in length, and extended
C. Columbus, the Incan highway, which was over 2,500 miles in length and
extended
D. Columbus, the Incan highway, being over 2,500 miles in length, was extended
E. Columbus, the Incan highway was over 2,500 miles long, extending

What is the correct ans according to you and why.
Thanks.

all others are grammatically incorrect

Undoubtedly option (b) that is!

Samy, I hate to disagree with our anonymous guest, but I'm feeling the urge. Lets take a quick look at each answer choice individually:

The greatest road system built in the Americas prior to the arrival of Christopher
Columbus was the Incan highway, which, over 2,500 miles long and extending from
northern Ecuador through Peru to Southern Chile.

A. Columbus was the Incan highway, which, over 2,500 miles long and extending
-though the modifier which correctly describes highway, the "sentence" is actually a sentence fragment, as the which needs to be followed by a verb (preferably "was")

B. Columbus was the Incan highway, over 2,500 miles in length, and extended
-the use of extended in the absence of which was is incorrect; the proper construction should be extending (as extended gives the impression that the road was intentionally lengthened rather than simply existing between two points).

C. Columbus, the Incan highway, which was over 2,500 miles in length and
extended
-since the phrase the Incan highway is set off by commas, the entire introductory modifier is describing the Incan highway. As a result, the which is unnecessary since it creates a sentence fragment.

D. Columbus, the Incan highway, being over 2,500 miles in length, was extended
-BEING IS BAD!!!!

E. Columbus, the Incan highway was over 2,500 miles long, extending
-The introductory phrase The greatest road system built in the Americas prior to the arrival of Christopher
Columbus properly describes the Incan highway. Furthermore, the subordinate phrase extending from
northern Ecuador through Peru to Southern Chile provides additional information about the length of the highway in a manner that is grammatically correct.

Though tricky, the correct answer is E.

-dan

In E, doesn't the phrase "extending from northern Ecuador through Peru to Southern Chile" suggest an ongoing activity? We have no idea if the road is still around today, which is why I eliminted E.

being is "bad" but not always incorrect in GMAT.

as being pointed out, usage of "extending" (present continuous tense) in D is incorrect.

also in B, ".....over 2,500 miles in length, and extended" is a run on sentence.

hence IMO D.


Thanks!

E should be correct

"extending from northern Ecuador..." is not used as verb. It's an adverbial modifier for "the Incan highway was over 2,500 miles long"

It's easier to think of adverbial modifier modifying the whole clause. But I think, specifically, it's modifying "was"
And adverbial modifiers links to the time frame of verb("was") it's modifying.

DPS has it correct. The -ing form as a modifier is NOT a verb. It is just modifying some verb or clause. In these cases, it usually functions in the same "time" as the verb/clause it modifies.

Dan,

Can you elaborate more on why B is wrong. I am still not totally convinced. If it said "was extended" then it is defenitely wrong, but "extended" alone seems ok for me.

Anyway, a side question, is apposition a prefered style to "anding" clauses?

Thanks in advance,

Me too would certainly go for E .

I drilled down to B and E for obvious reasons.

Whats the OA ?

E is correct.

B is out because "extended" has nothing to match with. We would need to know that it was extended BY something or someone. Moreover, the comma before "extended" is unnecessary, as it breaks up two modifiers that ought to be parallel.

Jonathan,
Columbus was the Incan highway, over 2,500 miles in length, and extended
I think the verb "extended" is parallel to " was"
...was the Incan highway and extended...
"over 2,500 miles in length" has been set off by a pair of comma. it modifies the noun "highway" and doesn't break the parallelism.

I know B sounds really not good. But it sound like a better option than E for me.
I don't get it why the "extending..." can act as a adverbial modifier to modify "was" because "was" is an Link verb. As u said before, this kind of adverbial modifier usually functions in the same "time" as the verb it modifies. But it doesn't make sense here coz "was" isn't an action.

can you explain this to me?
thanks a lot.

"was" is not a helping verb here; it's the main verb of the clause.

there are two requirements for the COMMA + -ING construction:
(1) it should be adverbial, modifying the entire previous clause;
(2) it should be attributed to the subject of the previous clause.

this -ing modifier (in choice e) satisfies both of these conditions, so we're good to go.

_________________
Being well-dressed gives a feeling of inward tranquillity [that] religion is powerless to bestow.
C.F. Forbes

Ron,

Can you PLEASE explain these above two conditions of COMMA + ING construction with some other example(s).

I always mess up in the sentences which used this construction. :(

Thanks!

GeeMate.

Please excuse that might be a basic question:

How do we identify an adverbial modifier, both in this case and in general for a sentence?

Thanks in advance.