Industrialization and modtern methods of insect control have

[gmatkiller_24]

Hi, Ron, just got a little bit doubt about choice C:

(C) while they have introduced some 100,000 dangerous chemical pollutants at the same time, which have gone virtually unregulated since they were developed more than 50 years ago.

If I remembered right, I saw one of your post that:

either one of the following structure is right:

XXX,which XXX,XXX (set off by a pair of comma)
XXX that XXX XXX(modifier not set off by comma)

but you cannot have XXXX,which XXXX. (that is wrong )

can I use this rule to eliminate C?

please correct me if I am wrong

[gmatkiller_24]

Hi, Ron, just got a little bit doubt about choice C:

(C) while they have introduced some 100,000 dangerous chemical pollutants at the same time, which have gone virtually unregulated since they were developed more than 50 years ago.

If I remembered right, I saw one of your post that:

either one of the following structure is right:

XXX,which XXX,XXX (set off by a pair of comma)
XXX that XXX XXX(modifier not set off by comma)

but you cannot have XXXX,which XXXX. (that is wrong )

can I use this rule to eliminate C?

please correct me if I am wrong

can i use the rule above to eliminate C, in addition to the wrong pronoun usage here " they " (ambiguity )

[RonPurewal]

no. if a modifier goes all the way to the end of the sentence, then, clearly, it can't have commas on both sides of it.

A Gutenberg Bible, which is more than 500 years old, was donated to the museum.
The museum has unveiled an exhibit featuring a Gutenberg Bible, which is more than 500 years old.

[RonPurewal]

on the other hand, the use of "which" in that example is so flagrantly wrong that you MUST be able to notice it IMMEDIATELY. (it would have to modify "time"-- clearly nonsense.)

if you did not IMMEDIATELY realize that "which" is used wrongly there, then your understanding of "which" is deficient.

[Chi HoC263]

RON my question is related to option A of this problem
A say :Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.

in one of your post u have said that :you also shouldn't use "having X..." unless having X actually has a direct effect upon the action in the main clause.
for example : having failed the exam 5 times already, M. was astonished when he received a passing mark.
i brought a cat ,having heard of two-for -one sale.--->correct (the main clause is the consequence of "having")
i brought a cat,having satisfied my need for a pet ----->wrong (the main clause is not the consequence of "having")
link :http://www.manhattangmat.com/forums/geologists-once-thought-that-the-molten-rock-known-as-lava-t722-15.html
doubt now if i go by this logic then option A can make sense for comma +having can work as cause
in other words we can view A as
having gone virtually unregulated since they were developed more than 50 years ago,Industrialization and modern methods of insect control have introduced some 100,000 dangerous chemical pollutants

If the __ing modifier comes BEFORE the main sentence, the relationship is reversed. You can't exchange the parts.

e.g.,
Having just finished a marathon, Mary was too tired to dance with her friends.
--> Here, the __ing modifier is the cause. It's still not the main part of the sentence, though, because its point is auxiliary; the main idea is that Mary was too tired to dance.

You could not put this __ing modifier after the main part of the sentence. If you did, the sentence would no longer make sense.

Hi Ron,

Can I conclude that if __ing modifier comes BEFORE the main sentence, then this __ing modifier means the cause of the main sentence? If __ing modifier comes AFTER the main sentence, then this __ing modifier would mean either the effect of the main sentence or some extra information provided to the main sentence?

Many thanks
Patrick

[RonPurewal]

Can I conclude that if __ing modifier comes BEFORE the main sentence, then this __ing modifier means the cause of the main sentence? If __ing modifier comes AFTER the main sentence, then this __ing modifier would mean either the effect of the main sentence or some extra information provided to the main sentence?

Many thanks
Patrick

'cause' is one possibility, but there are many possible relationships. the point is just that there should be a relationship.
e.g.,
Strolling down Highland Avenue, I saw a few businesses that I remembered from the 1990's. (legitimate sentence)
this is not 'cause and effect', but the relationship is clear.

[RonPurewal]

you do have the idea, though, in a more general sense:

• if '__ing' is already happening when the observation/event/thing in the main sentence takes place, then '__ing' should come before the main sentence.
(i was already strolling down the avenue when i made the observations in the sentence above.)

• if '__ing' is a consequence, result, or further characterization of the observation/event/thing in the main sentence, then '__ing' should come after the main sentence.

your observations about cause/effect are on point, but cause/effect is only one of many schemes that can be represented by these kinds of sentences.

[charmanineW924]

I knew that  "while" can be followed by an -ing participle,but from my understanding ,”while verbing ” = “while someone is /are /were /was verbing“. When the subject of the while clause is the same as the main clause ,and when the while clause is like “while someone is /are /were /was verbing”,so we can omit the subject and the verb (is /are ) in the while clause .
In this question ,if we say “while Industrialization and modern methods of insect control are introducing ...” is incorrect ,because we do not need use Progressive tenses.
If my understanding is wrong , I have some questions :
1)“while” in the “while doing ” means contrast or the simultaneous ?
2)Do we need the action in the “while doing ” is simultaneous with the action in the main clause ?

[RonPurewal]

I knew that  "while" can be followed by an -ing participle,but from my understanding ,”while verbing ” = “while someone is /are /were /was verbing“. When the subject of the while clause is the same as the main clause ,and when the while clause is like “while someone is /are /were /was verbing”,so we can omit the subject and the verb (is /are ) in the while clause .

i'm a bit confused here, because this ^^ seems unrelated to anything else in your post... yet you haven't asked an actual question about it.

also, i don't know the terminology ("participle"). so, if that is important, i may not be addressing the question you're trying to ask.

...anyway:

you can write things like this:
I like to sing songs while working.

you can also write things like this:
I like to sing songs while I work.

both of these sentences are fine. there are differences in emphasis/style, but of course this exam does not test such things (and, besides, precious few writers would be consciously aware of them).

i THINK your question is this:
"since the first one is correct, does that make the second one incorrect?"
if that's your question, then the answer is no. both of them are ok.

[RonPurewal]

In this question ,if we say “while Industrialization and modern methods of insect control are introducing ...” is incorrect ,because we do not need use Progressive tenses.

this construction does not appear in any of the choices. where do you see it?

[RonPurewal]

i believe i've written this elsewhere on the forum, but it bears repeating: "while" should ALWAYS describe things that are simultaneously true—regardless of whether it is used to indicate a contrast.

1)“while” in the “while doing ” means contrast or the simultaneous ?

it can do either, but, in most sentences of this type, it's only an indicator of simultaneity (e.g., Don't text while driving; I like to sing while working).

this is why "at the same time" is also used in the sentence at hand. ("at the same time" indicates simultaneity, of course—so "while" must be doing something more.)

[TooLong150]

on the other hand, the use of "which" in that example is so flagrantly wrong that you MUST be able to notice it IMMEDIATELY. (it would have to modify "time"-- clearly nonsense.)

if you did not IMMEDIATELY realize that "which" is used wrongly there, then your understanding of "which" is deficient.

Hi Ron,

Just to be clear, can we not eliminate C for its use of "which" since the plural verb indicates that it points to "pollutants" rather than to "time"? If we can't do this, why not and why doesn't the rule you stated in the post (https://www.manhattanprep.com/gmat/forums/post31162.html#p31162 apply?

[RonPurewal]

'which' is used specifically for 2 kinds of constructions. read here:
usage-of-which-t746-15.html#p104933

thanks for finding that (very old) post, by the way; i updated it.

[RonPurewal]

also—
even IF "which" were more flexible, your particular logic here still would not work, because "at the same time" is not modifying "pollutants"—it's describing the whole larger action that contains the word "pollutants".
you could only stick a modifier on "pollutants at the same time" if "pollutants at the same time" were a phrase that made sense by itself as a noun+modifier... which it isn't.

[RonPurewal]

ok, wait, i went and looked back at the original problem, and there is no "which" anywhere in any of the choices. hm? why are we discussing a choice that does not even exist?

DO NOT TRY TO "EDIT" GMAC PROBLEMS!
DO NOT INVENT YOUR OWN CHOICES TO THEM!

really, don't, guys.

are there two or more versions of this problem floating around?