What is Surface, when Opponent is "Jiří Vaněk"?
CREATE TABLE table_name_31 (surface VARCHAR, opponent VARCHAR)
SELECT surface FROM table_name_31 WHERE opponent = "jiří vaněk"
### Context: CREATE TABLE table_name_31 (surface VARCHAR, opponent VARCHAR) ### Question: What is Surface, when Opponent is "Jiří Vaněk"? ### Answer: SELECT surface FROM table_name_31 WHERE opponent = "jiří vaněk"