RBBmba@2014 wrote:

GMATGuruNY wrote: "A participle (VERBed or VERBing) omitted from the second clause must appear in the SAME FORM earlier in the sentence.".

My question was DOES the above aspect hold good in case of BOTH the following situations -

1. When comparison involves NO change in tense (i.e. SAME tenses)

If the verb in the second clause is THE SAME as that in the first clause, then any participle omitted from the second clause will AUTOMATICALLY appear in the same form in the first clause.
John is running faster than Mary is.
Here, the verb implied in the second clause (is running) is the same as that in the first clause, so the participle omitted from the second clause (running) automatically appears in the first clause.
In this case, there is no need to vet the omitted participle.

2. When comparison involves change in tenses (i.e. DIFFERENT tenses)

When there is a change in tense, then any participle omitted from the second clause must appear in the same form in the first clause.

GMATGuruNY wrote: D: the site of an ancient civilization flourishing at the same time as those [did]
Here, those lacks a plural antecedent.
Eliminate D.

on the top of the abovementioned issue, isn't the following also an error in D ?

in this sc,DID stands for a complete Verb=>FLOURISH (or FLOURISHED),but here DID can NOT stand for the Verb-ing modifier flourishing .

thoughts ?

ngk4mba3236 wrote:

GMATGuruNY wrote: D: the site of an ancient civilization flourishing at the same time as those [did]
Here, those lacks a plural antecedent.
Eliminate D.

on the top of the abovementioned issue, isn't the following also an error in D ?

in this sc,DID stands for a complete Verb=>FLOURISH (or FLOURISHED),but here DID can NOT stand for the Verb-ing modifier flourishing .

thoughts ?

I would be skeptical of an answer choice in which does/do/did serves to refer to a preceding VERBing modifier.
Generally, does/do/did serves to stand in for the simple present tense form or past tense form of a preceding VERB.

GMATGuruNY wrote:

ngk4mba3236 wrote: in this sc,DID stands for a complete Verb=>FLOURISH (or FLOURISHED),but here DID can NOT stand for the Verb-ing modifier flourishing .

thoughts ?

I would be skeptical of an answer choice in which does/do/did serves to refer to a preceding VERBing modifier.

so,i think, we can say this is a valid error. right ?

also, another reason to eliminate D could be: a clause can't be parallel to a verb-ing modifier. correct ?

GMATGuruNY wrote:Generally, does/do/did serves to stand in for the simple present tense form or past tense form of a preceding VERB.

I guess,does/do/did serves to stand in for the present perfect tense also.

OA of an official sc: Since 1990 the global economy has grown more than it did during the 10,000 years from the beginning of agriculture to 1950.

thoughts ?

ngk4mba3236 wrote:also, another reason to eliminate D could be: a clause can't be parallel to a verb-ing modifier. correct ?

I would be skeptical of an answer choice in which a clause is compared to a VERBing modifier.

GMATGuruNY wrote:Generally, does/do/did serves to stand in for the simple present tense form or past tense form of a preceding VERB.

I guess,does/do/did serves to stand in for the present perfect tense also.

OA of an official sc: Since 1990 the global economy has grown more than it did during the 10,000 years from the beginning of agriculture to 1950.

thoughts ?

I cited this SC in my second post.
Here, did stands in for the SIMPLE PAST TENSE FORM of the antecedent verb has grown.
Conveyed meaning:
Since 1990 the global economy HAS GROWN more than it GREW during the 10,000 years from the beginning of agriculture to 1950.