Why does the Book of Mormon mention Bellows (1 Nephi 17:11), Brass (2 Nephi 5:15), Breast Plates &Copper (Mosiah 8:10), Gold and Silver currency (Alma 11), Silver (Jarom 1:8), and Steel Swords (Ether 7:9)?

• 为什麽《摩门经》提到了风箱（尼腓一书十七章十一节），黄铜（尼腓二书五章十五节），胸牌和铜（摩赛亚书八章十节），金银货币（阿尔玛书十一章），银（雅龙书一章八节）和铁剑（以太书七章九节）?