document.write ("<b>上一篇</b>：<a href='/DocHtml/699/2014/2/25/7650678334643.html'>代数式（第1课时）</a><br><b>下一篇</b>：<a href='/DocHtml/699/2014/1/16/1891370434641.html'>Unit 12  You’re supposed to shake hands</a>")