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>
  <query-continue>
    <alllinks galcontinue="济南大学粒子物理|77" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="首页" />
      <page pageid="4" ns="2" title="用户:宋玉坤" />
      <page pageid="19" ns="0" title="理论力学" />
      <page pageid="28" ns="0" title="科研笔记" />
      <page pageid="85" ns="0" title="济南大学粒子物理" />
    </pages>
  </query>
</api>