外径48mm.壁厚3.0mm,长度6m,的Q235脚手架钢管怎么能计算出这根钢管重量是多少
2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16 2025-01-22 07:57:16家里的窗户框是木头做的时间大概十年了最近起了很多这种黄色的泡是怎么回事
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