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="BallanceValencia386" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="12328" ns="0" title="B" />
      <p pageid="1206" ns="0" title="B-S公式" />
      <p pageid="9318" ns="0" title="B353 互联网+实验室" />
      <p pageid="9315" ns="0" title="B634-2 视频会议室/虚拟仿真实验室" />
      <p pageid="12049" ns="0" title="BDMI-TA" />
      <p pageid="7" ns="0" title="BIAOGe" />
      <p pageid="2452" ns="0" title="BOT模式" />
      <p pageid="9965" ns="0" title="BUILD —— 机械结构组件" />
      <p pageid="9171" ns="0" title="BalcomRieger899" />
      <p pageid="7162" ns="0" title="BaldwinCarrell598" />
    </allpages>
  </query>
</api>