zoezhuyan wrote:
Hi experts,
I totally got the reason why eliminate D.
but I am still curious whether "having been sighted" can be an adjective ?
it might not be the point of this question but it can help me to understand "having" because I am sunk in "having" recently, I have no idea when "having" is correct, when incorrect.
and I have another question
OE say: B) also, without punctuation, the phrase on the surface of the Sun the Sun’s poles or equator is ungrammatical and makes no sense.
It's hard for me to understand , genuinely want your help
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Hi sayantanc2k,
Does it mean add a comma as following,
Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots that never have been sighted on the surface of the Sun , the Sun’s poles or equator.
it confused me a lot if add comma like this,
so the part after the added comma is noun phrase, right?
in an another word, the surface of the sun is the same as the sun's poles or equator, hm.. feel strange,
that's my confusion and sorry for my implicit previous post.
thanks a lot
have a nice day
>_~
Dear
zoezhuyan,
I'm happy to respond.
I see that my brilliant colleague
sayantanc2k already responded, but I will add a little more.
As
sayantanc2k, the structure "
having been sighted" is a perfect participle. Any participle can act as a noun or verb modifier. Be careful in your terminology, though: just because a participle acts as a noun modifier, we can't call it an "
adjective." Technically, when a participle acts as a noun modifier, it is an "
adjectival phrase"--that is a phrase that acts as a adjective--but it is not simply an "
adjective."
The problem with (D) is the incorrect structure "
although" + [participle]. The word "
although" is a subordinate conjunction, designed to open a dependent clause: it is designed to have a full bonafide [noun] + [verb] clause after it. A participle cannot take the place of a full clause.
For (B), I think the OE gives only half the story. Part of the problem is that, when we have a list, we need commas:
X, Y, or Z. That's one issue, but the deeper problem is the breech in logic. The prompt tells us quite clear: "
Sunspots . . . are visible as dark spots on the surface of the Sun ..." Even if we know absolutely nothing about
sunspots, we need to take that as an article of faith: sunspots are dark spots on the surface of the sun.
Given that, (B) makes the incredibly illogical statement: "
Sunspots . . . never have been sighted on the surface of the Sun ..."
If sunspots are defined as dark spots on the surface of the sun, that implies that somebody had to see these dark spots on the surface of the sun at some point, and so the statement that they have never been seen on the surface of the Sun flies in the face of fact! That, I would say, is the real problem with (B).
My friend, do not be naive in trusting the OE given in the
OG. The GMAT official questions, in the
OG and in GMAT Prep, are among the best test questions on the planet: I am simply in awe of their high quality. By contrast, the OE vary wildly: some are good, some are mediocre, some leave out important things, and some every make incorrect statements. Every release questions has been on the GMAT: it had to undergo rigorous testing before appearing on the GMAT, and then it garnered mountains of data while it was on the GMAT. Every question in the
OG or on GMAT Prep has hundreds of thousands of data points behind it, supporting its high quality. By contrast, when they wrote the
OG, somebody (probably a starving grad student) had to write the explanations; perhaps they were proofread once or twice, but these have undergone absolutely no statistical feedback procedure. I write questions as part of my job. Of the hundreds of questions I have written, only a handful of my very best questions approach the quality of official question. By contrast, I and all the experts on GMAT Club regular give better explanations than those in the
OG. Don't be surprised if the OE in the
OG doesn't say everything or misses the point. Come here if you want high quality explanations.
My friend, does all this make sense?
Take very good care of yourself, my friend.
Mike