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中国防水展开展在即,彩虹建材盛装待放

As soon as he had spoken, the Tin Man began to chop, and in a short time the tree fell over with a crash, whereupon the Scarecrow's clothes fell out of the branches and rolled off on the ground. Dorothy picked them up and had Winkies carry them back to the castle.

什么是金刚石砂轮？它和普通砂轮有什么不同？