CREATE TABLE table_2189 ("Year ( s ) " FLOAT, "Commentator" TEXT, "Dual Commentator" TEXT, "Spokesperson" TEXT, "Channel" TEXT)

which channels had spokesperson arina sharapova and no dual commentator
SELECT "Channel" FROM table_2189 WHERE "Spokesperson" = 'Arina Sharapova' AND "Dual Commentator" = 'No Dual Commentator'
SELECT "Channel" FROM "table_2189" WHERE "Dual Commentator" = 'No Dual Commentator' AND "Spokesperson" = 'Arina Sharapova'