中级 难度星级:☆☆★★★
知识点:交叉用9根火柴,怎样摆放,才能摆出6个正方形? +hwMUT1BrcvSi8ltLQ/Yk7c4OfAW4f/HC3s+z/WZPcVs/THbnGU3ekNz7gyrYdXz