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<style>
blockquote {
  margin-top:0;
  margin-bottom:0;
  border:1px solid black;
}
</style>
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<body>
<blockquote id="quote">This blockquote should have user agent margins for the left and right but the top and bottom margins should be 0.</blockquote>
<blockquote id="quote">This blockquote should have user agent margins for the left and right but the top and bottom margins should be 0.</blockquote>
</body>
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