New techniques in thermal-scanning photography, a process that records

New techniques in thermal-scanning photography, a process that records radiation from surface areas , have made it possible to study in greater detail than ever before the effects of calefaction, or warming, of a river

With (C) for the errors highlighted above...

Well ,I am still not convinced by the OA, and confused between B and C.
Yes, I agree that have does appear nice.
BUT as per my knowledge in GMAT it is preferred to use Simple tense as much as possible unless the sentence is not grammatically wrong AND perfect tenses are generally not used.
Can anybody please correct me..??

Thanks a lot sir,
Sir , the tell me whether my reasoning is wrong??
The reason for which C is the correct answer is because the option stresses on the effect of new technologies
And this the effect is still IN THE PRESENT

Suramya

Hi

Don’t you feel that there is no difference between B and C as far as new techniques are concerned? C is better because of the superior word order; in B, the placement of ‘than ever before’ after the river is changing the meaning.

New techniques in thermal-scanning photography, a process that records radiation from surface areas, makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before.

(A) makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before
SV error : Techniques(plural) makes (singular) : incorrect
(B) make it possible to study, in greater detail, the effects of calefaction, or warming, of a river than ever before

modification error (2 way looking modifier) 'in greater details'
1. Study in grater details
2. effects in greater details

(C) have made it possible to study in greater detail than ever before the effects of calefaction, or warming, of a river
Correct
(D) make possible the study of the effects of calefaction, or warming, of a river in greater detail than it ever was before
comparison error ;

(E) has made it more possible than ever before to study in greater detail the effects of calefaction, or warming, of a river
same as A : Incorrect


Experts pls comment.

Hi GMATNinja,

Please shed some light on this question.

Thank you.

daagh
Can you evaluate my reasoning to eliminate B
"in greater detail" is separated by comma on both the side, making it a non essential modifier
That means sentence should work without it . If we remove "in greater detail", then the sentence becomes
make it possible to study, in greater detail, the effects of calefaction, or warming, of a river than ever before
we have "than" in the sentence for which there will be no comparison element . Hence choice will be incorrect
Please let me know

Thanks in Advance

Priyanka

I think it is a modifier problem in B." Than ever before" modifies 'in greater detail' but in B, they are placed far apart. Perse, 'than ever before' in B seems to describe the warming of a river.

For example, if we say that Tom's score is higher than before, we need not amplify that his previous scores were lower than the score now, as this comparison is easily understood.

the pronoun "it" is being used "before" the antecedent (to study) ? is this correct in option C?

Bro have a few doubt in this question,

1. In option A and B, what is "it" referring to? Is it mandatory

2.
Option A : Option to study the effects of calefaction, or warming, of a river in greater detail
Option C : made it possible to study in greater detail than ever before the effects of calefaction,

Study is of calefaction, so shouldn't the modifier be together and hence elimiante C?



3. Option B
possible to study, in greater detail, the effects of calefaction, or warming, of a river

Analysis of option B :
a) in greater detail is between two commas making it non-essential, however it seems to be important to convey the meaning of the passage, on this basis can I eliminate B?
b) Similarly will it apply to " , or warming , "

Option C : How is the usage of "have made" correct? New technique means recently discovered and we use past perfect when saying something started in the past but continues in the present.

Hey, could you please clarify why 'it' is correct in C? Would be great if you provide me with some approach how to assess if 'it' is correct in these type of sentences.

It is a placeholder 'it' here.

It is possible to study 18 hrs a day.
It is possible that he complained to the manager.

'It' is a placeholder subject.

Sure, you substitute "it" with "?" (What).

So, the question you would ask is:

...have made ? possible...

Answer: to study in greater detail than ever before the effects of calefaction, or warming, of a river.

So, the above phrase (to study...a river) is the intended antecedent of "it".

The catch here is that this antecedent is used after the pronoun. However, this is quite acceptable.

p.s. Our book EducationAisle Sentence Correction Nirvana discusses this specific usage of "it". Have attached the corresponding section of the book, for your reference.

Hi ExpertsGlobal5 chetan2u,

I am still unclear on the usage of "it" in this question. I believe that "it" is used here as a placeholder and does not necessarily have an antecedent.

Please can you let me know if my understanding is correct?

Thanks in advance!

New techniques in thermal-scanning photography, a process that records radiation from surface areas, makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before.

Option Elimination -

(A) makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before - SV issue.

(B) make it possible to study, in greater detail, the effects of calefaction, or warming, of a river than ever before - It is not a perpetual phenomenon, so "have made" is preferred. Moreover, "than ever before" should be placed next to what "than ever before" modifies. "River"? No. "greater detail than ever before."

(C) have made it possible to study in greater detail than ever before the effects of calefaction, or warming, of a river - ok

(D) make possible the study of the effects of calefaction, or warming, of a river in greater detail than it ever was before - One issue is that the focus in option C is on the effects, but in option D, the focus has shifted to the study itself. Moreover, "than it was ever before" is redundant. The sentence before this phrase, "makes possible the study of the effects of calefaction, or warming, of a river in greater detail," already, in a way, says that we are studying in greater detail. "it" refers to "the new techniques have made the study of the effects possible" which itself is wrong as a pronoun "it" can't refer to a clause or is it a placeholder? Ambiguous.

(E) has made it more possible than ever before to study in greater detail the effects of calefaction, or warming, of a river - SV issue.