<li><b>Alkaline fuel cells (AFCs):</b> AFCs were used in the Apollo space program. They are highly efficient but require pure hydrogen and oxygen.</li>
<a href=https://carsinspections.com/transmission/transmission-of-a-car-definition/>https://carsinspections.com/transmission/transmission-of-a-car-definition/</a>
</ul>
<h3>Upholstery Cleaner</h3>