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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="〈千年村〉プロジェクトとは" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="2235" ns="0" title="Comments" />
      <p pageid="2304" ns="0" title="EditorsHelp" />
      <p pageid="2291" ns="0" title="News" />
      <p pageid="3105" ns="0" title="〈千年村〉からまなぶ" />
      <p pageid="2189" ns="0" title="〈千年村〉の事例からまなぶ" />
      <p pageid="2187" ns="0" title="〈千年村〉を「共同体」からみる" />
      <p pageid="2179" ns="0" title="〈千年村〉を「環境」からみる" />
      <p pageid="2205" ns="0" title="〈千年村〉を「集落」からみる" />
      <p pageid="2185" ns="0" title="〈千年村〉をたたえる" />
      <p pageid="2186" ns="0" title="〈千年村〉をつづける" />
    </allpages>
  </query>
</api>