| 摘要 |
<p>The pool cover consists of a platform, of metal, synthetic materials, timber, glass, etc., and a surface to fit the environment. The platform has folded or lamella-like side elements. It is raised by hydraulically, electrically or mechanically driven props. A single prop is located in the middle of the pool, and two or three props are positioned in the pool, in its wall, or outside it. The cover is effective in preventing dirt and other objects from falling in the pool.</p> |
