老J是搞机电的？这里的机械设计让俺太佩服了，特别是缝纫机和火车~根本不用高科技，只要高智商：）

来源: qiasini 于 2011-12-17 19:14:20 [旧帖] [给我悄悄话] 本文已被阅读：次

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