PHP DOMDocument::loadHTML(）[DOMDocument.loadHTML]:htmlParseE

我试图从某些网页中获取"链接"元素。不过我不明白我做错了什么。我得到以下错误：

严重性：警告

消息：DOMDocument:：loadHTML（）[DOMDocument.loadHTML]：htmlParseEntityRef:实体中没有名称，行：536

文件名：controllers/test.php

线路编号：34

代码中的第34行如下：

      $dom->loadHTML($html);

我的代码：

            $url = "http://www.amazon.com/";
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
    if($html = curl_exec($ch)){
        // parse the html into a DOMDocument
        $dom = new DOMDocument();
        $dom->recover = true;
        $dom->strictErrorChecking = false;
        $dom->loadHTML($html);
        $hrefs = $dom->getElementsByTagName('a');
        echo "<pre>";
        print_r($hrefs);
        echo "</pre>";
        curl_close($ch);

    }else{
        echo "The website could not be reached.";
    }