NASA’s methodical approach to the exploration of Mars has not yet answ

The parallelism looks pretty OK to me here. "NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether... those traces can still exist....

The trouble appears to be that pesky little modifier in the middle of the underlined portion: "...presuming such life forms having left fossil traces to begin with..." It would be fine to say "presuming such life forms left fossil traces to begin with" -- but I can't make any sense of the phrase "having left" in this case. You could say something like "having left a mess in his pigpen, Wilbur proudly trotted off to make a mess somewhere else" -- the "having + verb" needs to be the first of two actions, as it is in my silly example. But I can't come up with any interpretation of "having left" in (A) that would make any sense at all, especially when one of the answer choices is clearly much better.

Plus, there's no good reason to use the word "can" in this situation. Is NASA trying to figure out whether the fossil traces can still exist -- or does NASA just want to know whether the fossil traces actually still exist? I'd argue for the latter.

So we can get rid of (A).


Well, this is a hot mess: "NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether... can those traces still exist.... Um... "whether can those traces"? Seriously? That's ridiculous -- and the word "can" doesn't make any sense in this context anyway, as discussed in answer choice (A).

The modifier in the middle of the underlined portion is a much smaller problem, but it's still a problem: "if it is presumed" isn't nearly as clean as just "presuming." But that's a minor issue.

(B) is out.


Much better! The heart of the parallelism is completely fine here: "NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether... those traces still exist.... No problem. And it's great that the word "can" has been removed, too.

The modifier in the middle of the underlined portion is also much better than the versions in (A) and (B): "presuming such life forms left fossil traces to begin with" makes sense here. Or at least more sense than the alternatives. Keep (C).


We have some issues here, even if we ignore that modifier in the middle of the underlined portion: "NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and...if they can still exist.... The first problem is that there's no good reason to use "if" after the "and." I suppose that you could argue that it's not parallel to "whether", but more importantly, I'm pretty sure that "if" can only be used in a conditional statement (otherwise known as an "if-then statement": "if I eat fourteen dosas and seven kati rolls, then I will be happy...") on the GMAT, and (D) isn't a conditional statement. In these situations, the GMAT always seems to prefer "whether" over "if."

Plus, you could argue that the pronoun "they" is ambiguous, because it could plausibly refer back to "life forms" or "fossil traces." Pronoun ambiguity isn't an absolute rule on the GMAT, but it's also not ideal if you can avoid it.

And then we still have the issue with the word "can", as described in (A). So we can get rid of (D), too.


(E) has two of the same errors as (D): "they" is arguably ambiguous and "if" is not as good an option as "whether." Plus, there's no reason to say "presuming such life forms to have left fossil traces to begin with." Just "left" would have been fine.

So (E) can be ditched, and (C) is the best we can do.
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Awaiting OA

NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether, presuming such life forms having left fossil traces to begin with, those traces can still exist in some moist recesses of the cold and arid planet.

A. and whether, presuming such life forms having left fossil traces to begin with, those traces can
Traces can? Having left?

B. and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces
Whether can ? Redundancy

C. and whether, presuming such life forms left fossil traces to begin with, those traces
Correct

D. and, presuming such life forms did leave some fossil traces to begin with, if they can
Whether if? Redundancy

E. and, presuming such life forms to have left fossil traces to begin with, if they
Whether if? Redundancy

Just looking at the grammar and structure alone,

A. and whether, presuming such life forms having left fossil traces, to begin with, those traces can --- having left is wrong diction, we need a verb rather than a participle here.

B. and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces -- use of whether and if in the same clause is incongruous.

C. and whether, presuming such life forms left fossil traces to begin with, those traces -- the correct choice

D. and, presuming such life forms did leave some fossil traces to begin with, if they can -- 1. The use of the conditional is wrong'. We have a dilemma here and therefore, only 'whether' is the correct diction.

E. and, presuming such life forms to have left fossil traces to begin with, if they-- the same problem as in D.

The only nagging doubt is whether the modifier clause in the second part starting with 'presuming can modify 'those traces' in C as well as A?
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A) "Having" participle makes no sense here
B) "Whether can those traces" is a fragment, "if" clause also could be written better
C) Correct
D, E) Not parallel -> "Whether if" is not correct.

(A) and whether, presuming such life forms having left fossil traces to begin with, those traces can
The issue with (a) is the "having". Since there is no form of be (is/was/are/be) "having" isn't acting as a verb, but rather a modifier.

(B) and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces
Issue: "whether..can" is illogical

(C) and whether, presuming such life forms left fossil traces to begin with, those traces
Good.

(D) and, presuming such life forms did leave some fossil traces to begin with, if they can
"Whether... and..if" aren't parallel? Use if in "if/then" constructions (careful though as the "then" can be omitted) otherwise use whether.

(E) and, presuming such life forms to have left fossil traces to begin with, if they
"Whether... and..if" aren't parallel. Use if in "if/then" constructions (careful though as the "then" can be omitted) otherwise use whether.
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Done, thanks for pointing!
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NASA’s methodical approach to the exploration of Mars has not yet answered the questions of
whether biological life forms ever emerged on Mars
and whether, presuming such life forms
having left fossil traces to begin with,
those traces can still exist in some moist recesses of the cold and arid planet.


(A) and whether, presuming such life forms having left fossil traces to begin with, those traces can

(B) and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces

(C) and whether, presuming such life forms left fossil traces to begin with, those traces

(D) and, presuming such life forms did leave some fossil traces to begin with, if they can

(E) and, presuming such life forms to have left fossil traces to begin with, if they

IMO C
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in option C. the modifying thing in between whether, presuming such life forms left fossil traces to begin with, those traces. Can anyone tell me how a verb and subject pair exists in this modifier

Not sure if I understand your question correctly; life forms is the subject and left is the verb.
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How can the structure be like whether(subordinate) ,clause,clause isn't this comma splice
Whereas what i thought it should whether, modifier, clause
And if the structure is what i thought then how can a subject verb pair exsist in a modifier

Posted from my mobile device

Rule #1 for Sentence Correction: do not invent rules.

It's fine to have a subject and verb as part of a modifier. These constructions are quite common. For example:

Tim, who fancies himself an excellent father, occasionally forgets to feed and clothe his children.

Here, "who fancies" is a subject-verb pair within a modifier describing Tim. This is perfectly acceptable. Notice that "who fancies himself an excellent father" cannot stand on its own, so we don't have to worry about the possibility of a run-on or comma splice.

Similarly, we could have:

Assuming that Tim would like to stay out of prison, his wife decided to give their two-year-old some dried food in a bowl.

Again, we have a subject and verb - Tim would like - within a modifier, this one describing Tim's wife. And because "assuming Tim would like to stay out of prison" cannot stand on its own, we don't have a comma splice.

The same is true in the example you cited. "Presuming such life forms left fossil traces to begin with" contains a subject and verb, but because it's a modifier that cannot stand on its own, there's no problem here.

I hope that clears things up!
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GMATNinja The above examples you cited use a subordinate marker of a sort. In the first example who (a relative pronoun) follows a verb and is sort of a dependent clause , and in second example there's "that" which again marks the beginning of a dependent clause where as I don't see one in our question.
Could it be the case that the line below even if it has a subject verb pair and does not have a subordinate marker(Or maybe has a marker I don't know is a marker)
"presuming such life forms left fossil traces to begin with" is still a dependent clause because it does not standalone and does not convey an independent idea , and hence there's no comma splice as two independent clauses need a conjunction but one independent and one dependent do not.
I am sorry you had to read through my mess. Hope I was able to articulate my thought

Ah, that's interesting. You're right that the official example lacks a word such as "that" or "who" to clearly indicate that we're not dealing with an independent clause. You have to use context. And now that I think about it, you could have two sentences that appear to be structurally identical, but function in very different ways. Consider:

1) Assuming Tim fails his driving test, his family will have to do a fair amount of walking next week.

In this example, the portion in red serves as a modifier and cannot stand on its own -- this is similar to the construction you asked about. It's true that there's no "that" or "who" to make it obvious that we're dealing with a dependent clause, but "Assuming Tim fails his driving test," simply doesn't make any sense on its own. It's not as though there are various versions of Tim, and here we get the "assuming Tim" as opposed to the "thinking Tim" or the "swimming Tim." Because there's only one independent clause, this sentence is fine.

However, we could also write:

2) The panicking student failed his driving test, his family will have to do a fair amount of walking next week.

On the surface, this one looks the same as the first example. The sentence begins with an "-ing" followed by a subject and a verb. But this time, "the panicking student failed his driving test" can absolutely stand on its own. Because we now have two independent clauses separated by a comma -- instead of a modifier and one independent clause -- this version is a comma splice and would be incorrect.

The takeaway: usually when you have a dependent clause, there will be a structural clue to make this obvious. However, English is complicated ( ), and you do have exceptions ( ), so you need to be very careful not to go on autopilot. Make sure you're always thinking about context and logic.

I hope that helps!
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Much better! The heart of the parallelism is completely fine here: "NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether... those traces still exist.... No problem. And it's great that the word "can" has been removed, too. The modifier in the middle of the underlined portion is also much better than the versions in (A) and (B): "presuming such life forms left fossil traces to begin with" makes sense here. Or at least more sense than the alternatives. Keep (C).

Hi!

Can anyone please explain me that how a comma+verb-in modifier (presuming) makes sense here. I'm unable to understand how exactly is it modifying the previous action?

AnjuliM
It's actually modifying the phrase it's interrupting: "whether those traces still exist." This is a construction we encounter more in writing than in speech. The author adds some condition or qualifier before proceeding: "I want to invite you, if you are interested, to see our museum." In this case, it's a way of managing the complicated meaning. We haven't established two things, and the second depends on the first. 1) Did life forms ever exist on Mars? 2) If they did exist AND they left fossil traces, are those traces still around?
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NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether, presuming such life forms having left fossil traces to begin with, those traces can still exist in some moist recesses of the cold and arid planet.


(A) and whether, presuming such life forms having left fossil traces to begin with, those traces can

Having left – always this kind of wordings ‘having left’ are wrong in Gmat.

(B) and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces

It- ambiguous , whether can – cant come together

(C) and whether, presuming such life forms left fossil traces to begin with, those traces

No errors

(D) and, presuming such life forms did leave some fossil traces to begin with, if they can

Did leave – No reason for using did leave rather than ‘left’. If – condition .’ If condition’ should be used for conditional statement. But here, We are searching for answer whether biological life forms can still exist in some moist recesses of the cold and arid planet.

(E) and, presuming such life forms to have left fossil traces to begin with, if they

Same error – If condition . they – ambiguous. In this statement, they can refer back to life forms . But , we are talking about fossil traces . So, E is out

GMATNinja egmat karishma

DmitryFarber

I have a question in (C). Here's a substituted version of C.

NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether, presuming such life forms left fossil traces to begin with, those traces still exist in some moist recesses of the cold and arid planet.

I discarded this option because I felt 'presuming' cant modify 'those traces' and the verb+ing modifier should definitely make sense with the subject. Since those traces can't really presume, I felt passive construction 'it is presumed' was needed.


Now only (B) offers that. Every forum discussion discards (B) for whether..can construct.
If its an idiom then I can take that learning whether should not be accompanied with 'can'
But here's my thought:

It's perfectly (IMO) fine to say-
NASA's approach has not yet answered the questions of
(i) whether life forms ever emerged
(ii)and whether can those traces still exist

Basically (ii) is saying the approach is yet to answer whether those traces can even exist (like saying: Scientists are yet to confirm whether water can exist at 300 degrees Celcius).

Please help. Thank you.

I got it right, But I have a query
Is "they" in D & E ambiguous?? they can refer to traces or life forms?

Besides is there any rule that noun modifier cannot jump a verb to modify noun, so if that's the case then "they" is not going to be ambiguous!!
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jim441

Ambiguity is basically a matter of meaning. As long as the intended meaning is clear, the pronoun is not ambiguous. If you're given a choice between a pronoun and an actual noun, then the noun is safer, all else being equal. However, the GMAT won't always give you that choice, and there are plenty of valid answers in which a pronoun has multiple *potential* antecedents, but only one that is logical.

In this case, we do have a "fix" for "they" in the correct answer, so the writers may have seen the pronoun as potentially confusing. However, I wouldn't rule a choice out on that basis alone. After all, if we're talking about finding fossils traces of life, then surely it's the fossils, and not the life forms themselves, that we are looking for.

As for "jumping," there is some leeway for this even on modifiers. But pronouns, such as "they" are not modifiers at all. They are stand-ins for nouns, and as long as the intended meaning is clear, they can stand in for any noun in the sentence, no matter how far away.
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