发布时间:2025-01-20 04:49:59
你把桥墩的柱子用纸张折成三角状,这个桥柱子从侧面看应该是个梯形,因为
桥墩的最大承重力就应该是个三角状,柱子最下面接地面的横截面越宽,桥墩的承重力就越大,梯形越高,柱子底下接地面的就要越宽越好,这样做的话,应该就可以了望
在琴行看了几个品牌的琴问一下英昌的钢琴和雅马哈的还有海伦的哪个牌子有优势
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