帮忙写歌正则表达吧,弄了半天没搞明白.

	$content ='<span class="description"><ul><li><a href="/download/T/h/e/The-North-Face-womens-mens.gif" class="popup-570-550" target="_blank">The North Face Size Chart</a> </li><li>Breathe deeply and slow your racing brain in the Be Calm Tank.</li><li>VaporWick technology sweeps moisture away from your skin for quick evaporation to leave you feeling spectacular.</li><li>Structured V-panel neckline.</li><li>Racerback styling allows arms complete range of movement.</li><li>Wide waistband with ruched side seams.</li><li>Eye-catching burnout design.</li><li>Logo at center back.</li><li><em>Sports bra not included.</em></li><li>73% polyester, 27% cotton.</li><li>Machine wash cold, tumble dry low.</li><li>Imported.</li><li class="measurements">Measurements:<ul><li>Length: 25 in</li></ul></li><li>Product measurements were taken using size XS. Please note that measurements may vary by size.</li><li><a href="/c/measurements" target="_blank">View This Model Measurements</a></li></ul></span>';	preg_match_all('/<li>(^<a*?)<\/li>/si',$content,$matches);	print_r($matches);