这个是入口shiyan.php

{

define('ACC','true');
require('itshi.php');
include('shiyan.html');

}

itshi.php
{

defined('ACC') || exit('ACC 未定义');
$take = 1888;

}

shiyan.html
{

<a href="two.php" target="_blank">点击我</a>
<p>
    <?php echo $take; ?>
</p>
<a href="shiyan.php" target="_blank">返回实验</a>

}

{
two.php

require('itshi.php');

}
当我运行shiyan.php的时候，点击a标签进入two.php怎么提示ACC未定义啊，不是一开始就在shiyan.php就定义了ACC吗？