document.write ("<b>上一篇</b>：<a href='/DocHtml/699/2014/5/5/3923978534663.html'>探究光的反射定律</a><br><b>下一篇</b>：<a href='/DocHtml/699/2014/4/10/1111066534659.html'>Unit 3 What colour is it?</a>")