strip-html.md

Remove HTML tags

<?php

$html = '<div class="cc">
    Explore the use of simple 
    <a class="keyword_w_elaboration">technologies</a>
    <div class="elaboration" style="text-decoration:none">
        <div class="elaboration_controls"></div>
        <div class="elaboration_content">
            <div class="keyword_elaboration_title">technologies</div>
            things that extend human abilities (e.g., axe)  &nbsp;
        </div>
    </div> 
    to extend their abilities
</div>';

$text = strip_tags($html);
$text = html_entity_decode($text);
$text = trim(str_replace("\xc2\xa0", ' ', $text));
$text = preg_replace('/(\s\s+|\n|\t)/', ' ', $text);

echo $text;

Output

Explore the use of simple technologies technologies things that extend human abilities (e.g., axe) to extend their abilities

Demo: https://3v4l.org/1ZdRs