CREATE TABLE table_56224 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

Who was the away team at MCG?
SELECT "Away team" FROM table_56224 WHERE "Venue" = 'mcg'
SELECT "Away team" FROM "table_56224" WHERE "Venue" = 'mcg'