镀锡丝上小颗粒
<DIV class=xxxxAd><SCRIPT type=text/javascript></SCRIPT><SCRIPT src="http://pagead2.googlesyndication--.com/pagead/show_ads.js" type=text/javascript></SCRIPT><SCRIPT src="http://pagead2.googlesyndication--.com/pagead/js/r20110315/r20110321-2/show_ads_impl.js"></SCRIPT><SCRIPT>google_protectAndRun("ads_core.google_render_ad", google_handleError, google_render_ad);</SCRIPT></DIV>请大侠们指点：热镀0.03有间断性黑色小颗粒，刮也刮不掉，是哪些方面产生的？