What is Circuit, when Series is ASTC Round 4?
CREATE TABLE table_44750 (
    "Date" text,
    "Series" text,
    "Circuit" text,
    "City / State" text,
    "Winner" text,
    "Team" text
)
SELECT "Circuit" FROM table_44750 WHERE "Series" = 'astc round 4'
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: What is Circuit, when Series is ASTC Round 4? ### Input: CREATE TABLE table_44750 (
    "Date" text,
    "Series" text,
    "Circuit" text,
    "City / State" text,
    "Winner" text,
    "Team" text
) ### Response: SELECT "Circuit" FROM table_44750 WHERE "Series" = 'astc round 4'