| http://www.w3.org/ns/prov#value | - a flat structure made of sturdy materials such as but not limited to wood, steel, aluminum, plastic, composite or equivalent rigid material, with surface area similar but not less than that of top platform 111 to avoid toppling.As best shown in FIGS. 3 and 4, in one embodiment the elevation system 300 consists of threaded rod portion 117, adjusting lever 112 and supporting housing 113.
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