<p>(To stand in) Persepolis in modern Iran and look out, as Darius the first (must have done) at the immense (sweep of fields and mountains) is (to grasp) the vastness of the ancient Persian Empire.(No Error)</p>
<p>Must have done is incorrect due to the incorrect tense.</p>
<p>I had that but the answer says it is no error.</p>
<p>Oh, I was just going by what the previous person who answered this said. In that case, I have no idea.</p>
<p>Is there a comma missing from the sentence as you posted it?</p>
<p>(In other words, did you copy this correctly?)</p>
<p>Either way, why did you choose “must have done”?</p>
<p>There is no error in the sentence, because there are two tenses. There is a lerson that is pondering something. They are in the present tense. Darius is a past character being referred to who did the same action as the person did except in the past. The person in the present is putting himself in Darius’ shoes and trying to feel what Darius felt in the past except only in the present.</p>
<p>I know it’s confusing. Let me know if you need clarification.</p>
<p>person* ^^^</p>
<p>“Sweep of the fields and mountains” doesn’t sound right.</p>
<p>But at the same time it could just be the way ETS writes, so in that case it could be No Error.</p>
<p>When you absolutely have no idea what the answer is on an SAT question, it’s always best to skip it entirely.</p>
<p>@sitara that TOTALLY makes sense. Thank you very much</p>