2/3 +3 / 4 +1 / 12 = 8/12 +9 / 12 +1 / 12 = 18/12 = 3/2 =1.5米的“http:// zhidao.baidu.com / API / getdecpic？picenc = 8b307a6865f821“> 1.5米根原丝的长度
