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>
    <allpages apcontinue="Demo_Class_1_经验分享" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="1499" ns="0" title="Boom, Boom, Ain&#039;t it great to be crazy?" />
      <p pageid="5097" ns="0" title="CODE.ORG课程" />
      <p pageid="4954" ns="0" title="Celestia教学活动之七" />
      <p pageid="5016" ns="0" title="Celestia教学活动之七工单" />
      <p pageid="5015" ns="0" title="Celestia教学活动之七幻灯片" />
      <p pageid="5014" ns="0" title="Celestia教学活动之八" />
      <p pageid="1500" ns="0" title="Cinderella剧本节选" />
      <p pageid="1501" ns="0" title="Cinderella自编自演4课时教案" />
      <p pageid="21" ns="0" title="Cmc课程开发" />
      <p pageid="1502" ns="0" title="Come little leaves" />
    </allpages>
  </query>
</api>