Which opponent used a grass surface?
CREATE TABLE table_name_1 (
    opponent VARCHAR,
    surface VARCHAR
)
SELECT opponent FROM table_name_1 WHERE surface = "grass"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which opponent used a grass surface? ### Input: CREATE TABLE table_name_1 (
    opponent VARCHAR,
    surface VARCHAR
) ### Response: SELECT opponent FROM table_name_1 WHERE surface = "grass"