XSL转换问题，简单，做出一定给分

Question

<?xml version="1.0" encoding="GB2312"?>
<root>
<a>
<b aa="" bb="">1</b>
<c aa="" bb="">2</c>
<d aa="" bb="">3</d>
<e aa="" bb="">4</e>
</a>
</root>需要XSL文件，形成如下文件
<?xml version="1.0" encoding="GB2312"?>
<root>
<b aa="" bb="">1</b>
<d aa="" bb="">3</d>
<root>

Answer 1

<?xml version="1.0" encoding="gb2312"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
          <xsl:output method = "xml" indent = "yes" encoding = "gb2312" /> 
          <xsl:template match = "FeatureSet" > 
               <root> 
                    <xsl:copy-of select = "a/b" /> 
               </root> 
          <xsl:template> 
<xsl:stylesheet>