找到了有效的解决方案，

This is the post item

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    <pubdate>2013-02-20 10:33:58</pubdate>
    <dc:creator>
    <![CDATA[ David Jennings ]]>
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    <title>Title</title>
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    <![CDATA[ABCD]]>
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    <![CDATA[ ]]>
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    <category domain="category" nicename="blog"> <![CDATA[ blog ]]> </category>
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    <wp:meta_key>_thumbnail_id</wp:meta_key>

    <wp:meta_value><![CDATA[888888]]></wp:meta_value>

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This is the attachment item

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    <pubDate>Mon, 07 Apr 2014 07:04:24 +0000</pubDate>
    <dc:creator><![CDATA[admin]]></dc:creator>
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    <excerpt:encoded><![CDATA[]]></excerpt:encoded>

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