Question: WHAT COMPETITION HAS Marian Sandu?
SQL: SELECT "Competition" FROM "2-16680101-1" WHERE "Res." = 'Marian Sandu';

Question: WHAT SCORE WAS ON 1999-05-31?
SQL: SELECT "Score" FROM "2-16680101-1" WHERE "Date" = '1999-05-31';

Question: WHAT OPPONENT HAD A SCORE OF 5:5?
SQL: SELECT "Opponent" FROM "2-16680101-1" WHERE "Score" = '5:5';