Barron's PSAT Prep Grammar Section

<p>I’ve recently taken a couple of Barron’s practice PSAT’s and I find the grammar section hard for some reason. Even after I’ve read their explanation, I still don’t quite understand why this question is wrong:</p>

<p>Standoffish and reserved, Charles Lindbergh was uncomfortable with the applause he <em>received from the crowds which have cheered his historic flight</em>.</p>

<p>(the astericks indicate the unerlined portion that needs to be corrected)</p>

<p>my answer: received from the crowds that cheered his historic flight</p>

<p>correct answer: receives from the crowds which cheer his historic flight</p>

<p>Can somebody please explain why this answer is correct?</p>