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>
    <allredirects garcontinue="MindManager/简单教程" />
  </query-continue>
  <query>
    <pages>
      <page pageid="673" ns="0" title="CSS" />
      <page pageid="895" ns="0" title="CSS技术文章" />
      <page pageid="1525" ns="0" title="CSS选择符" />
      <page pageid="2200" ns="0" title="Discuz!X/微商店/数据库字典/pre plugin qq send log" />
      <page pageid="2199" ns="0" title="Discuz!X/微商店/数据库字典/pre plugin qq send pool" />
      <page pageid="1600" ns="0" title="Discuz!X/数据库字典" />
      <page pageid="1179" ns="0" title="Google Chrome" />
      <page pageid="1516" ns="0" title="IE6下PNG-24位图片问题集合" />
      <page pageid="1017" ns="0" title="ImageMagick 在windows下的安装" />
      <page pageid="676" ns="0" title="MindManager" />
    </pages>
  </query>
</api>