一天 ,苏格兰数学家莱福德看他的儿子在玩颜色板 ,他儿子从玩具盒中把红的、兰的、黄的颜色各抽出两块来 ,相互调来调去 ,排成一行 ,莱福德看到六块板的顺序是 :黄红兰红黄兰 ,这种排列具有下面的特点 :( 1 )两块红板之间另有一块颜色板 ;( 2 )两块兰板之间另有二块颜色板 ;( 3 One day, the Scottish mathematician Lefford saw his son playing with color plates. His son took out two red, blue, and yellow colors from the toy box and tuned in and out, lined up. The order in which Ford saw the six boards is: Huang Honglan, Huang Honglan, this arrangement has the following characteristics: (1) There is another color board between the two red boards; (2) There is another between the two boards Two color plates; ( 3