CREATE TABLE table_251 ("Comparisons" TEXT, "Hub Base Class" TEXT, "Emulated Class" TEXT, "Semi-DDM Class" TEXT, "DDM Class" TEXT)

Is wireless combo keyboard and mouse support part of the DDM class?
SELECT "DDM Class" FROM table_251 WHERE "Comparisons" = 'Wireless Combo keyboard and mouse support'
SELECT "DDM Class" FROM "table_251" WHERE "Comparisons" = 'Wireless Combo keyboard and mouse support'