You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <parse title="API" displaytitle="API">
    <text xml:space="preserve">&lt;p&gt;&lt;a href=&quot;/index.php?title=Dennis%E7%9A%84%E7%9F%A5%E8%AF%86%E5%BA%93:Sandbox&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;Dennis的知识库:Sandbox（页面不存在）&quot;&gt;Dennis的知识库:Sandbox&lt;/a&gt;
&lt;/p&gt;
&lt;!-- 
NewPP limit report
Preprocessor visited node count: 2/1000000
Preprocessor generated node count: 12/1000000
Post-expand include size: 31/2097152 bytes
Template argument size: 0/2097152 bytes
Highest expansion depth: 2/40
Expensive parser function count: 0/100
--&gt;
</text>
    <langlinks />
    <categories />
    <links>
      <pl ns="4" xml:space="preserve">Dennis的知识库:Sandbox</pl>
    </links>
    <templates>
      <tl ns="4" xml:space="preserve">Dennis的知识库:Sandbox</tl>
    </templates>
    <images />
    <externallinks />
    <sections />
    <iwlinks />
    <properties />
  </parse>
</api>