帮忙写歌正则表述吧,弄了半天没搞明白

帮忙写歌正则表达吧,弄了半天没搞明白.

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

什么正则表达式,可以把有
提取所有的li的内容.
写得我混乱了. 最后那个数组[1]应该大约是这样的.
matches[1][x]=Breathe deeply and slow your racing brain in the Be Calm Tank.
matches[1][x]=VaporWick technology sweeps moisture away from your skin for quick evaporation to leave you feeling spectacular.
matches[1][x]=Structured V-panel neckline.
.....
matches[1][x]=Sports bra not included.
matches[1][x]=73% polyester, 27% cotton.
...
简单说就是排除

里面以
------解决方案--------------------
preg_match_all('/

(?!/siU',$content,$matches);