| 摘要 |
A stairway having an alternating series of risers and treads wherein two risers and a tread form a step structure for use in constructing the stairway. The step structure including a first riser having a front portion and a rear portion, a tread having a support surface and an opposite surface, a second riser having a front portion and a rear portion, and wherein the tread is positioned between the rear portion of the first riser and the front portion of the second riser and wherein the second riser of one step structure becomes the first riser of the next-up step structure.
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