hear|verb|to receive sound through the ears; to receive news about
mouth|noun|the part of the face that a person puts food into and speaks from, see <a href="http://spotlightenglish.com/images/uploads/spotlight_body_diagram.png?v=1488398231" class="less_important_link overlay" id="img_spotlight_body_diagrampng" rel="#overlay">spotlight_body_diagram.png</a>
see|verb|to know or sense through the eyes; to understand or know
tired|adjective|having less strength because of work or exercise; needing sleep or rest
experiment|noun|a test or trial carried out to prove if an idea is true or false, or to discover something
experiment|verb|to test
why|conjunction|the reason for which (&ldquo;I do not know why she did it.&rdquo;)
why|conjunction|the reason for which (&ldquo;I do not know why she did it.&rdquo;)
