Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_26464364_1 (us_air_date VARCHAR, _number VARCHAR)
### Question:
On which date did episode # 18 air in the U.S.?
### Answer:
SELECT us_air_date FROM table_26464364_1 WHERE _number = 18