标签越有过滤器，就可以通过下面的示例这样的小插件来增强它。

<?php
/**
 * Plugin Name: br after more-Tag
 * Description: Add content of var $extra_more after more-Tag
 * Version:     0.0.1
 */

! defined( \'ABSPATH\' ) and exit;

add_filter( \'the_content_more_link\', \'custom_more_link\', 9999 );
function custom_more_link( $more_link ) {

    $extra_more = \'<br>\'; // here add your break

    return $more_link . $extra_more;
}

add_filter( \'the_content\', \'fb_more_link\' );
function fb_more_link( $content ) {

    // only on single posts
    if ( ! is_single() )
        return $content;

    // adsense code
    $my_content = \'<br>\';

    // replace more tag
    $content = preg_replace(\'/<span id\\=\\"(more\\-\\d+)"><\\/span>/\', $my_content, $content);
    return $content;
}