<p>If anyone is wondering, these are from the back of RR.</p>
<p>A ranger at the skate park [explained to] the students that an extrememly large percentage of [their] wildlife [relies on] insects [as] a source of food. No error.
Why is "their" incorrect?</p>
<p>[Some] advanced math concepts [are] difficult for students to understand because [they] [call for] students to think three-dimensionally. No error.
Why is "they" incorrect?</p>
<p>Thank you!</p>
<ol>
<li>Singular subject..skate park
2.nvm...Bigb14 got it right</li>
</ol>
<p>their is wrong, it should be its. Skate park is singular.</p>
<p>This one is ambiguous, because it doesn't say if "they" is referring to students or concepts.</p>
<p>At meadow, first of all, the subject is "some." second of all, it isn't a singular subject. The sentence is ambiguous.</p>
<p>The second one is a terrible question, in my opinion. I hope it wasn't on the actual SAT?</p>
<p>OHHH my bad I completely misinterpreted what #1 was trying to say lol. For some reason, I thought the ranger was talking about animals that the students had (i.e. pets)...lol I don't know what I was thinking...</p>
<p>Also is "some" one of those wacky singular collective nouns? I don't think so, because "some is" sounds really weird while "some are" sounds correct. I figured they referred to some. Concepts call for for students, while students would be called upon for?</p>
<p>ANd ^ no it's not from an SAT...just doing some drills in RR.</p>
<p>^I have no idea what you said about the second one, but it has nothing to do with "some." I'll repeat, the sentence is ambiguous because it doesn't clarify if "they" is referring to to "students" or "concepts"</p>
<p>I think [their] is simply unnecessary and awkward. (Although, technically, wild animals are a public natural resource. ;) ) Incidentally, is the beginning of the sentence perhaps supposed to read "state park" instead of "skate park"?</p>