But the DRAM and NAND semiconductor industries have gone from boom to bust in the face of rising prices and the abundance of falling prices. Will it be any different this time? Or is the need for mobile device memory and disk replacement sufficient to continue to delay the abundance until the foreseeable future? There are 3, 4, 5, 6, 8, 10 and 12 cylinders of the engine. The arrangement of cylinder mainly includes direct column, V shape, W shape, etc. 3. Modern enterprise period