user: Question: What kind of competition was it at San Siro at 18:30 GMT?
Columns: ['Date', 'Time', 'Competition', 'Opponent', 'Ground', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['17 July 2007', '15:30 GMT', 'Friendly Match', 'China Olympics Team', 'Riscone di Brunico', '3-0']
SQL:

assistant: SELECT "Competition" FROM "Table" WHERE "Ground" = 'San Siro' AND "Time" = '18:30 GMT';