Experts estimate that

[kramacha1979]

Gprep

Experts estimate that ten times as much petroleum exists in sources like tar sands, heavy oil , and perhaps even in shale than in conventional reservoirs

A < same >
B sources like tar sands, heavy oil , and perhaps even in shale than are
C such sources as tar sands, heavy oil , and perhaps even in shale as are
D such sources as tar sands, heavy oil , and perhaps even shale as
E such sources as tar sands, heavy oil , and perhaps even shale than

Couple of things
a) ten times as much ...as Idiom issue, kills A, B and E
b) like is used to introduce eg's here, need such..

Between C and D what's the deal.

OA :D

[stock.mojo11]

Gprep

Experts estimate that ten times as much petroleum exists in sources like tar sands, heavy oil , and perhaps even in shale than in conventional reservoirs

A < same >
B sources like tar sands, heavy oil , and perhaps even in shale than are
C such sources as tar sands, heavy oil , and perhaps even in shale as are
D such sources as tar sands, heavy oil , and perhaps even shale as
E such sources as tar sands, heavy oil , and perhaps even shale than

Couple of things
a) ten times as much ...as Idiom issue, kills A, B and E
b) like is used to introduce eg's here, need such..

Between C and D what's the deal.

OA :D

OA is indeed D. You narrowed it down to C & D. Thats good

C is wrong because it uses perhaps "in" shale. The whole comparison is now changed and seems as if we are comparing P among TS,HO, S and Conventional resources

Shale is supposed to be an example of other sources. D keeps that comparison intact.

[hhale]

One other quick question on this post:

Between choices
D: such sources as tar sands, heavy oil, and perhaps even as
E: such sources as tar sands, heavy oil, and perhaps even shale than

How do we know the correct answer is D? Is it because the correct idiom is "ten times as much petroleum exists in X as in Y and" and "ten times as much petroleum exists in X than in Y" is unidiomatic?

Let me know...

[RonPurewal]

One other quick question on this post:

Between choices
D: such sources as tar sands, heavy oil, and perhaps even as
E: such sources as tar sands, heavy oil, and perhaps even shale than

How do we know the correct answer is D? Is it because the correct idiom is "ten times as much petroleum exists in X as in Y and" and "ten times as much petroleum exists in X than in Y" is unidiomatic?

Let me know...

ya -- "N times as much as" is idiomatic; "N times as much than" isn't.

[iharden]

Hey Ron,
It looked as if you were referencing the the wrong "as much..as..". I now see that the middle "as" is acting as a distracting middle man. Recognizing the "as"'s the apply to the idiom make the correct answer pretty obvious. Thanks.

[RonPurewal]

Hey Ron,
It looked as if you were referencing the the wrong "as much..as..". I now see that the middle "as" is acting as a distracting middle man. Recognizing the "as"'s the apply to the idiom make the correct answer pretty obvious. Thanks.

that other "as" is part of the construction such ... as ... (such sources as tar sands...)
glad everything is clear now.

[wun866]

Hi Ron，
I am confused of the use of comparison.
For the comparison between "petroleum exists in sources" and "in conventional reservoirs", why helping word "do" is not need to add after "as" to refer to exists?
Please help me, thx!

[RonPurewal]

Hi Ron，
I am confused of the use of comparison.
For the comparison between "petroleum exists in sources" and "in conventional reservoirs", why helping word "do" is not need to add after "as" to refer to exists?
Please help me, thx!

it's not necessary.

fortunately, you don't have to worry about this -- you just have to find the two expressions in the comparison, and check whether they're properly parallel to each other.

note point #2 here:
https://www.manhattanprep.com/gmat/foru ... ml#p113659

[wun866]

Hi Ron，
I am confused of the use of comparison.
For the comparison between "petroleum exists in sources" and "in conventional reservoirs", why helping word "do" is not need to add after "as" to refer to exists?
Please help me, thx!

it's not necessary.

fortunately, you don't have to worry about this -- you just have to find the two expressions in the comparison, and check whether they're properly parallel to each other.

note point #2 here:
https://www.manhattanprep.com/gmat/foru ... ml#p113659

Thankyou Ron
It really works!

[RonPurewal]

you're welcome.

[thanghnvn]

there are 3 kinds pattern of comparison
1, adverb comparison
circulation is lower today than yesterday. do not insert "that/those" in the second clause. there is no second kind of circulation in the second clause. (there is a similar question in gmatprep)
2. subject or adjective comparison. "that/those " is used or full noun in the second clause is used
persons at havard is better than those at hanoi business school.
persons at havard is better than academics at hanoi business school
3. zero subject comparison
3 times as many institutions charge tuition fee lower than 8000 usd as charge 16000usd ( this is from gmatprep)
we can not add any words in the second clause of comparison.

meaning and logic make those pattern. so, dont worry too much.

[Sage Pearce-Higgins]

Thanks for your contribution, thanghnvn. Although I agree with your broad categories, I would recommend any student read the chapters on comparisons in the SC strategy guide to get acquainted with the nuances and traps involved.

[JbhB682]

Hi Experts - i have heard of the idiom as + adjective + noun + as

in option D - what is the idiom - is it as + clause as ?

[esledge]

Hi Experts - i have heard of the idiom as + adjective + noun + as

I'm not as familiar with that. More commonly, it's as + adjective + as and if you want to throw a noun in there, it would be parallel: X is as + adjective + noun + as Y, where X and Y are nouns. In conversation, I guess I've heard as + adjective + noun + as , such as "He's as funny a comedian as his sister is," but it strikes me as ... non-standard English.

in option D - what is the idiom - is it as + clause as ?

I think this idiom is still "as much...as," but the sentence word order is just complex.

Ten times as much petroleum exists in Place A as in Place B.

means the same as the awkwardly-phrased:

Petroleum exists in amounts that differ by location: ten times as much in Place A as in Place B.

I'm not suggesting that this is how you should ever phrase this, but just pointing out that the parallel elements are "in Place A" and "in Place B," so the idiom is the parallel marker "as much as."