2012 Oct SAT writing questions

<p>Until relatively recently humans were thought to be uniquely self-aware, (scientists now know) that most chimpanzees and orangutans can recognize their own reflections.
(b) but scientists now know
(c) however, scientists now know</p>

<p>The answer is b.
Why is original sentence wrong? Isn't that until work as a conjunction?</p>

<p>Although Daniel Gabriel Fahrenheit was far from (being) the (only) eighteenth-century scientist (to propose) a temperature scale, (but his) was no of the few that were widely used.
The answer is (but his).
Why is that wrong. Isn't that it refer to his temperature scale?</p>

<p>The 1st one creates a run-on sentence. If you want it to be correct you need to have a “.” after the self-aware, the “but” is fixing that.</p>

<p>For the 2nd question, the “but” is unnecessary because the sentence allready starts with Although.</p>

<p>As an addition to the explanation provided by TomerHd, “however” in the first question is used as a “linking adverb”/“transition word” to connect two independent clauses. Each clause is full sentence, and hence the need for a period. The choice of “but” is correct. Here “but” is used as a conjunction.</p>