Nobodyknowswhoinventedthepencilorwhenitwasinvented.ASwi...
問題詳情：Nobodyknowswhoinventedthepencilorwhenitwasinvented.ASwiss(瑞士人)describedapencilinabookin1565.Hesaiditwasapieceofwoodwithlead(鉛)insideilsweren’tpopularatthattime,andpeoplecontinuedtowritewi...