九个数字选三个有多少组合怎么算

简介：Looking at the heart of the spirit tree with burning eyes, he stepped forward and touched it. Feeling the warm and smooth touch, Xiao Xiaobai couldn't help but feel a little surprised and excited: Such a good thing, when I reach the Qi stage, I can barely refine it. Yes, you can refine a magic weapon! What kind of monk is he without a magic weapon in hand?