<p>Meteorites are of great interest to **astrophysicists, since this is how they obtain information **about the chemical composition of early solar systems.</p>
<p>A. astrophysicists, since this is how they obtain information
B. astrophysicists, who obtain from them information
C. astrophysicists because information is obtained by them
D. astrophysicist; they obtaion imfroation this way
E. astrophysicists, which is how they obtaion information</p>
<p>The answer is B but isn't a conjuction needed because the two clauses are independent?</p>
<p>Nah. Go to [Comma</a> - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Comma]Comma”>Comma - Wikipedia) and read the part about “Separation of clauses” under the “Uses” sub-heading.</p>
<p>There are not two independent clauses there. “who obtain from them information about the chemical composition of early solar systems” is a dependent clause. “who” (a relative pronoun) introduces that relative clause. Additional examples of dependent, relative clauses:</p>
<p>I know of a house [that has three windows].</p>
<p>I want a friend [who will give me money].</p>
<p>Independent clauses need to be logically whole by themselves. “that has three windows,” for example, is not logical by itself.</p>
<p>Also, do you understand why (A) is wrong?</p>
<p>Just in case you don’t understand Silverturtle’s explanation of independent/dependent clauses, here’s my way of telling:</p>
<p>An independent clause can stand by itself as a complete sentence. Using the example above, the first clause is independent:</p>
<p>Meteorites are of great interest to astrophysicists</p>
<p>Just by seeing that, you wouldn’t know if there is anything else to the sentence; it makes sense this way. It feels and sounds like a complete sentence.</p>
<p>A dependent clause feels short, empty, and is not a complete sentence. Using the 2nd clause from the correct answer from the question above (B):</p>
<p>who obtain from them information about the chemical composition of early solar systems</p>
<p>If you read that (and just that), doesn’t it seem unfinished? If you were to write that in an English paper as a sentence, your teacher would probably deduct points for writing an incomplete sentence.</p>
<p>I hope that helps. It’s not the proper grammatical explanation, but I’ve found that it makes sense to people, so I thought I’d just throw it out there.</p>
<p>A is wrong because the comma isn’t needed, since acts like because?
So who obtained from them information about the chemical composition of early solar systems is dependent because the antecedent for who is in the first part of the sentence?</p>
<p>
</p>
<p>No. Although the comma is unnecessary, it is not incorrect. (A) is wrong because “this” has no antecedent.</p>
<p>I guess I better go read your guide again:(</p>
<p>I would choose B. I’m noy in grammar good, but just other choices R making “bad sound” or “sounds bad”.</p>