PHP SIMPLE_HTML_DOM_PARSER未在特定网站上显示某些链接

Question

我目前正在学习如何使用＆＃39; SIMPLE_HTML_DOM_PARSER＆＃39;来抓取网站。而我正面临困难， 我们可以看到的页面click here有3列

＆＃39; Si no＆＃39;，＆＃39; code＆＃39;，＆＃39; course name＆＃39;和它下面的许多链接。所以当我执行下面的代码时

    <?php
    include 'simple_html_dom.php';
    $html = file_get_html('http://www.sitttrkerala.ac.in/index.php?r=site%2Fdiploma-syllabus-courses&prog=CM');
    foreach($html->find('td') as $element){
    echo htmlspecialchars($element);
    echo "<br>";
    }
    ?> 

以上代码仅返回 -

<td style="text-align:center">Sl No.</td>
<td class="style1">Code</td>
<td class="style1">Course Name</td>

这些td下有多个链接，甚至没有一个链接显示。 我也试过

    echo htmlspecialchars($element->href);//nothing bieng displayed

我认为返回的dom不包含那些链接，请参阅此代码

    include 'simple_html_dom.php';
    $html = file_get_html('http://www.sitttrkerala.ac.in/index.php?r=site%2Fdiploma-syllabus-courses&prog=CM');
    echo ($html);
   ?>

返回的输出是

Government of Kerala
Department of Technical Education
Login

    SITTTR Login
    Member Login

Govt. Logo
State Institute of Technical Teachers' Training & Research, Kalamassery
HMT Junction, Kalamassery - 683 104, Phone: 0484-2542355,
Fax: 0484-2542355, E-mail: jd_cdc@yahoo.com, sitttr@gmail.com
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DIPLOMA SYLLABUS
Sl No.  Code    Course Name        //empty there should be multiple links under it
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State Institute of Technical Teachers Training & Research
HMT Junction, Kalamassery - 683 104
Phone: 0484-2542355, Fax: 0484-2542355
E-mail: jd_cdc@yahoo.com, sitttr@gmail.com
Website: http://www.sitttrkerala.ac.in
Contact Us | Sitemap | Disclaimer | RTI

为什么链接没有返回我尝试卷曲但是失败了。在过去的2周里坚持了。