Ice-polished rocks - MGMAT SC text clarification

[RonPurewal]

I know this is nonsense but could you please shed some light on how to treat such ambiguity?

Thank you for your reply!

If the red thing is true, there is no ambiguity.

[Tadashi]

Hi Ron,
May I ask you a question about option B, OA.
"in which great ice sheets existed in what are now temperate areas"
why use "what" here.
can I use "in which great ice sheets existed where are now temperate areas" ?



please help me.
ARIGATO
Tadashi

[RonPurewal]

First and foremost, let me re-iterate a piece of advice I've given you several times: Do not edit GMAC's sentences.
Doing so will almost always create issues that are not tested on the exam.

The combination of "there are areas" and "where..." is redundant / unnecessarily wordy. You'd use either ... in what are now temperate areas or ...where the climate is now temperate.

[Tadashi]

Thanks for your advice!

I just want to learn about the difference between "where+clause" and "what+clause".
I guess I understand now.
what + clause = something + which + clause
where + clause = some place which + clause

We can use prep. before "what+clause" since what is a noun, while we can not use prep. before "where+clause" since where is a adv.

Would you like to comment on my thought?

ARIGATO
Tadashi

[RonPurewal]

"Where ___" can also act as a noun.

I have no idea what this chemical does or where it is found.

If one more person starts a conversation by asking me where I live or what I do for a living, I'm going to scream.

It's rare—but not impossible—for this kind of 'noun' to occur at the beginning of the sentence:
That the XXX tribe buried a huge pile of treasure is beyond doubt. Where they buried it, though, is still completely unknown.

[Tadashi]

Thanks for your examples!

[RonPurewal]

Sure.

[batman08]

Hi Ron,

Thanks a lot for your explanation in this thread.

Could you please explain what is wrong with option D -
when great ice sheets had existed in current temperate areas ?

Considering we can't use "had existed" to eliminate this option, is the phrase "current temperate areas" incorrect ?

Thanks!

[RonPurewal]

Hi Ron,

Thanks a lot for your explanation in this thread.

Could you please explain what is wrong with option D -
when great ice sheets had existed in current temperate areas ?

Considering we can't use "had existed" to eliminate this option, is the phrase "current temperate areas" incorrect ?

Thanks!

You need different tenses to switch the timeframe.

"Current temperate areas" are areas that exist now. These areas didn't exist back then. So, that option is nonsense.

[RonPurewal]

Analogy:
In the early 19th century, a few Mexican traders lived transiently in the region that is now the city of Las Vegas.
This makes sense.
Note the two timeframes:
"- "in the early 19th century ... lived"
- "that is now the city of LV"

*In the early 19th century, a few Mexican traders lived transiently in the current/modern/present city of Las Vegas.
Nonsense, unless these Mexican traders were capable of time travel!
"The current/modern/present city of Las Vegas" didn't exist back then. The traders couldn't have lived in it, because it wasn't there.

[JhanasC520]

Ron

Can u please explain what is wrong with Option C & Option E?

I am little confused with OG Explanations. In Option E, 'now' acts as an adverb but an adverb doesn't need to be close to verb. Why is E being discarded for this reason? Is there any ambiguity associated with placement of 'now'?

Option C -> Is it wrong because 'where' doesn't have any antecedent?

I also need to understand the right option B - 'What are now temperate areas'- Can what introduce a relative clause?

Thanks
Vijay

Adverbs get some leeway, but when there are more than 1 verb (or other item it should be modifying) in a sentence, the sentence can be unclear. In this case it is wrong because:

(E) when great ice sheets existed in areas now (that are temperate)

"that are temperate" is a clause describing the areas. Since now is left out of that clause, it is modifying when the ice sheets existed. They existed now is absurd, but structurally, this is the meaning of the sentence.

As for (C), let's strip away some fluff and see what happens:

(C) when great ice sheets existed where there were areas (now temperate)

The problem isn't that "where" is misplaced, it's that the word is illogical. Ice sheets existed where there were areas? Nope.

In the correct answer "what are now X" is a lesser-used expression that expresses the same meaning as "that are now X". The difference is whether they go before or after the modifier. "that" is much more versatile (and common) in life and on the GMAT:

great ice sheets existed in (what are now temperate) areas
is the same as:
ice sheets existed in areas that are now temperate

Dear Ron & Jlucero.

I doubt whether the explanation above is correct or not? "what are now X" is the same meaning with "that are now X" ?

if it is so, what is the difference, in this sentence, between the " in what are now temperate areas" and "areas now that are temperate".

many thanks for your reply.

[RonPurewal]

In "areas now...", now is attached to areas——implying that the ice sheets were in the versions of these areas that exist now. That's illogical; the ice sheets don't exist in the present.

[sukriti.bahl]

Dear Instructors,

I know that option D is wrong because of "had" and the phrase " in current temperate areas" , however, "had" always gives me a bad head ache..

What I want to understand is that - his studies led Louis Agassiz to propose the concept .....great ice sheets had existed......
My point is, his proposal came after his study.. In that case to show the time difference "had" should be correct... If not why?

Sorry if its a silly question.

Thanks

[RonPurewal]

two problems here.

1/
'propose' does not create a meaningful time sequence with anything.
basically, this sentence is 'he proposed [IDEA]' ... but then "IDEA" is an idea that totally makes sense all by itself. thus, any tenses within "IDEA" can't require a reference to anything outside "IDEA" (such as 'propose').

if that just looks like a meaningless bundle of abstraction, then let's look at some examples.

the following are all legitimate sentences:
We will all die in the year 2050.
If Hitler had been accepted to art school, he never would have become dictator of the Third Reich.
The dinosaurs were wiped out by a comet.
Ellen had never before heard any of the things I told her at the party.

therefore, the following are all legitimate sentences, too:
Smith said that we will all die in the year 2050.
Smith said that if Hitler had been accepted to art school, he never would have become dictator of the Third Reich.
Smith said that the dinosaurs were wiped out by a comet.
Smith said that Ellen had never before heard any of the things I told her at the party.

hopefully you see the point. (technically 'proposed' is not there—the past-tense verb is actually 'led'—but the same analysis applies.) you're trying to apply time-sequence rules to things that aren't actually a time sequence.

[RonPurewal]

...and

2/
'had __ed' IS NOT used for EVERY 'earlier event'. in fact, it's not even used for most 'earlier events'.

if two past events are merely in sequence, or aren't directly related at all, then they just appear in the normal past tense (unless there's some other reason to put them in a different tense).

Crum lived in Illinois until he was sixteen and then moved to Florida, where he stayed for the next forty years.

Arnold Schwarzenegger, who served as governor of California, did not grow up in the United States.

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