Sentence Correction

Test1-44. (26787-!-item-!-188;#058&002971)

Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth's interior and producing energy on a commercial scale, enough for efficient generation of electricity and heating factories and homes.

(A) and producing energy on a commercial scale, enough for efficient generation of electricity and heating
(B) and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat
(C) for energy production on a commercial scale, enough for generating electricity efficiently and to heat
(D) to produce energy on a commercial scale, enough for generating electricity efficiently and for heating
(E) to produce enough energy on a commercial scale for efficient generation of electricity and heat

Ans: [spoiler](D)[/spoiler]

mining heat

Is "mining" a noun or Ving?
If mining is Ving, maybe (A), (B) are better because "mining" and "producing" are parallel.

Yop! Kaijen I understood what u want to say -

mining heat

Is "mining" a noun or Ving?
If mining is Ving, maybe (A), (B) are better because "mining" and "producing" are parallel.

But pls dnt mind kaijen- I am giving u a suggestion - When I also started preparation for SC, I tried to do in that way (blindly following the rule mentioned in the book or study materials). But after consulting with different SC problems, taking some mock test and going thru OGs, I have found the fact that test-taker always try to get an answer which is quite straight forward, not too much wordy and another secret I will like to share with you all -
In the mock tests, I have found out maximum time that there will be at least two options which will have totally different approach to modify the underlined part of the qs. And if so, then just try to hit them first and maximum time one of them becomes the OA.
I know my words sound little risky and out-of-the-track but I just shared my findings with you. May be I am wrong!
Now Kaijen returning to ur qs, mining is a noun made by adding ING with the verb. Now this question does not appear to me as parallel construction totally. Except D, all the other options are having either idiomatic problem or problem related to sentence construction.
have u got my point, Kaijen? :

Thanks for your advice.
I guess the reason why I could't find the answer so quickly as you do is that I am not a native speaker. Sometimes when I come across a tricky question--like this one--all I can do is use my grammar to analyze it and find the best answer. Maybe I should try to understand the meaning of the sentence instead of relying only on grammar rules because it is very likely that all five choices are all grammatically correct.

Kaijen,
I am also not a native speaker of English. But to crack GMAT, u have to know the pattern generally test-takers follow and the approach to take to solve the problem. I was also in the same phase as u r now. Even still now I am sure that I will stubble if any unknown or little tricky SC (even easier to those I have solved)! But I have got much help from the documents posted in BTG and those documents are good to start with SC. So I will suggest you to go thru those documents (Spidey, Sahil and Rajat SC documents) before heading over some OG or some sample SC questions. Hopefully (a member of BTG) suggested me to do this and I have got help from those documents! Thanks Hopefully once again!
Kaijen, I will suggest you to download those dicuments from BTG and go thru those fitst.

IMO:D

d is right because mining is a process to produce energy and this energy is enough for generating and for heating
(A) and producing energy on a commercial scale, enough for efficient generation of electricity and heating - no parallelism, also flow of sentence parallels mining and producing
(B) and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat - flow of sentence parallels mining and producing
(C) for energy production on a commercial scale, enough for generating electricity efficiently and to heat -no parallelism
(D) to produce energy on a commercial scale, enough for generating electricity efficiently and for heating - correct
(E) to produce enough energy on a commercial scale for efficient generation of electricity and heat - enough is away from generating and heating,no parallelism

kaijen wrote:Test1-44. (26787-!-item-!-188;#058&002971)

Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth's interior and producing energy on a commercial scale, enough for efficient generation of electricity and heating factories and homes.

(A) and producing energy on a commercial scale, enough for efficient generation of electricity and heating
(B) and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat
(C) for energy production on a commercial scale, enough for generating electricity efficiently and to heat
(D) to produce energy on a commercial scale, enough for generating electricity efficiently and for heating
(E) to produce enough energy on a commercial scale for efficient generation of electricity and heat

Ans: [spoiler](D)[/spoiler]

Why is B wrong? Is it because it uses passive voice 'to be generated' or something else?

[quote="patanjali.purpose"][quote="kaijen"]Test1-44. (26787-!-item-!-188;#058&002971)

Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth's interior [u]and producing energy on a commercial scale, enough for efficient generation of electricity and heating[/u] factories and homes.

(A) and producing energy on a commercial scale, enough for efficient generation of electricity and heating
(B) and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat
(C) for energy production on a commercial scale, enough for generating electricity efficiently and to heat
(D) to produce energy on a commercial scale, enough for generating electricity efficiently and for heating
(E) to produce enough energy on a commercial scale for efficient generation of electricity and heat

Ans: [spoiler](D)[/spoiler][/quote]

Why is B wrong? Is it because it uses passive voice 'to be generated' or something else?[/quote]

Scientists have succeeded in mining heat ['to' not 'and'] for doing something and hence infinitive for purpose id used.

patanjali.purpose wrote:

kaijen wrote:Test1-44. (26787-!-item-!-188;#058&002971)

Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth's interior and producing energy on a commercial scale, enough for efficient generation of electricity and heating factories and homes.

(A) and producing energy on a commercial scale, enough for efficient generation of electricity and heating
(B) and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat
(C) for energy production on a commercial scale, enough for generating electricity efficiently and to heat
(D) to produce energy on a commercial scale, enough for generating electricity efficiently and for heating
(E) to produce enough energy on a commercial scale for efficient generation of electricity and heat

Ans: [spoiler](D)[/spoiler]

Why is B wrong? Is it because it uses passive voice 'to be generated' or something else?

No. First try to understand the meaning of the sentence here.

What have Scientists succeeded in? They succeeded in -- mining heat from the Earth's interior. Next question -- for?

Ans - to produce energy on commercial scale. - rest of the part is a list.

Format -
X,Y and Z. Choose D.

lunarpower wrote:

patanjali.purpose wrote:Why is B wrong? Is it because it uses passive voice 'to be generated' or something else?

(b) contains a fake parallel structure -- that is, it contains elements that appear grammatically parallel, but that aren't supposed to be grammatically parallel.
the intended meaning of the sentence -- which you can grasp by using your own intuition, and also by using the initial version of the sentence as a guide -- is that the electricity is used for (at least) two purposes:
(1) generating electricity,
(2) heating homes and factories.
these are the things that are supposed to be in parallel -- so it's the forms of "generate" and "heat" that must look the same. if the sentence puts other things in parallel, as choice (b) does, then it's incorrect.

Thanks a lot Ron. It makes lot of sense.

I have a follow up doubt: if B were 'and producing enough energy on a commercial scale for electricity to GENERATE efficiently and to heat", will this be correct?

Secondly, "electricity to be generated efficiently and to heat" - can I drop this choice also because ELECTRICTY is not the grammatical subject of TO BE GENERATED - it is someone else (BY Phrase - that is not mentioned) while subject of TO HEAT is ELECTRICTY itself. Therefore 2 sides of AND has 2 different subjects here when we require them to be same.

Thanks for your time.

regards,
Patanjali

This is a classic parallelism problem, touching upon simple vs complex gerunds. Simple gerunds such as "verb-ing" should never be parallel to complex gerunds such as "the/a/an+ verb-ing + of the..". Once you know this, B starts to look awkward and unparallel.

Mining heat from X to produce Y

"and" --> incorrect here.
See why "and" is inappropriate here
have succeeded for the first time in mining heat from the Earth's interior and producing energy on a commercial scale
=
succeeded for first time in doing X and doing Y.

above sentence is grammatically correct.. but logically doesn't make sense.

it means first time producing energy on commercial scale but that's not intention of author.
..[ energy might be produced on commercial scale by other methods ...]
first time in doing X from Z to product Y.
Between D and E.
D looks better.

A. and producing energy on a commercial scale, enough for efficient generation of electricity and heating --> Misplaced modifier. The modifier is modifying "commercial scale" where it should be placed near "energy". Also, "for efficient generation of electricity" and "heating" are not parallel. It should have been "for generating electricity and heating ". This sentence also perverts the intended meaning. The sentence should have been "Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth's interior to produce energy on a commercial scale,"

B. and producing enough energy on a commercial scale for electricity to be generated efficiently and to heat--> again it should be "to produce" and the underlined parts are not parallel.

C. for energy production on a commercial scale, enough for generating electricity efficiently and to heat--> underlined parts are not parallel.
D. to produce energy on a commercial scale, enough for generating electricity efficiently and for heating--> looks good. Underlined parts are parallel and "and" replaced by "to".

E. to produce enough energy on a commercial scale for efficient generation of electricity and heat --> underlined portion is wrong. It should be a noun / noun form (gerund) - "heating". Option E also changes the intended meaning of the sentence. Placement of enough is awkward here.
It should be D.