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_name_18 (release_date VARCHAR, release_format VARCHAR, country VARCHAR)
### Question:
What is the release date for the standard cd release format in north america?
### Answer:
SELECT release_date FROM table_name_18 WHERE release_format = "standard cd" AND country = "north america"