<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hr SYSTEM "hr.dtd">

<!-- 人力资源管理系统 -->

<hr>

   <employee no="3309">

       <name>张三</name>

       <age>31</age>

       <salary>4000</salary>

       <department>

            <d1name>会计部</d1name>

            <address>xx大厦</address>

       </department>

   </employee>

   <employee no="3310">

       <name>李四</name>

       <age>23</age>

       <salary>3000</salary>

       <department>

            <dname>工程部</dname>

            <address>xx大厦</address>

       </department>

   </employee>

</hr>

<?xml version="1.0" encoding="UTF-8"?>

<!ELEMENT hr (employee+)>

<!ELEMENT employee (name,age,salary.department)>

<!ARRLIST employee no CDATA "">

<!ELEMENT name (#PCDATA)>

<!ELEMENT department (dname,address)>

<!ELEMENT dname (#PCDATA)>

<!ELEMENT address (#PCDATA)>