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>
    <alltransclusions gatcontinue="CHfull|442" />
  </query-continue>
  <query>
    <pages>
      <page pageid="69" ns="0" title="청주 용두사지 철당간" />
      <page pageid="77" ns="0" title="안심사 영산회 괘불탱" />
      <page pageid="143" ns="0" title="청주 이항희 가옥" />
      <page pageid="146" ns="0" title="청주 지선정" />
      <page pageid="152" ns="0" title="청주 신전동 고가" />
      <page pageid="154" ns="0" title="청주 신영호 고가" />
      <page pageid="164" ns="0" title="청주 탑동 양관" />
      <page pageid="6662" ns="10" title="틀:CHpage" />
      <page pageid="7085" ns="0" title="고령신씨" />
      <page pageid="7286" ns="0" title="독립운동" />
    </pages>
  </query>
</api>