find('a,b') is slower than find('a')+find('b'), why?
<p><a href="http://jsperf.com/find-a-b-vs-find-a-find-b" rel="nofollow">jsperf's link</a></p>

<p>I'm not a jQuery expert(not even a good user), i haven't studied the whole source code of it (only a little part which can't help me solve this problem).</p>

<p>Can somebody explain this for me?</p>
