CREATE TABLE table_51889 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

Which Away team has a Venue of mcg?
SELECT "Away team" FROM table_51889 WHERE "Venue" = 'mcg'
SELECT "Away team" FROM "table_51889" WHERE "Venue" = 'mcg'