CREATE TABLE table_55718 ("Match" FLOAT, "Date" CLOB, "Competition or tour" CLOB, "Ground" CLOB, "Opponent" CLOB, "Score1" CLOB)

Which opponent has a date 21 jul 2007?
SELECT "Opponent" FROM table_55718 WHERE "Date" = '21 jul 2007'
SELECT "Opponent" FROM "table_55718" WHERE "Date" = '21 jul 2007'