<p><span style="font-size:20px;"><span style="color:#27ae60;">The Right Answer</span></span></p>
<p>This one is a straight <strong><span style="color:#8e44ad;">Math Strategy</span></strong> question. The colon indicates that the idea on the right should be a continuation of the idea on the left. On the right-hand side, we can see that it says "most of them knew very little about foreign countries". The blank (which also describes the same people) should be conveying this idea, something like "narrow-minded" or "parochial"</p>
<p>The best match for this blank is <span style="color:#27ae60;">insular</span>.</p>
<p><span style="font-size:20px;"><span style="color:#e74c3c;">The Wrong Answers</span></span></p>
<ul>
<li><span style="color:#e74c3c;">partisan:</span> This choice <b>has no evidence. </b>There is no evidence that the people were biased in any way.</li>
<li><span style="color:#e74c3c;">erudite:</span> This choice <strong>contradicts</strong> the logic of the sentence. The sentence says the people "knew very little", not "knew a lot"</li>
<li><span style="color:#e74c3c;">cosmopolitan:</span> This choice <strong>contradicts</strong> the logic of the sentence. If they were "cosmopolitan", they would be well aware of other countries</li>
<li><span style="color:#e74c3c;">imperturbable:</span> This choice <b>has no evidence. </b>There is no evidence about how calm the people were.</li>
</ul>