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_17 (call_sign VARCHAR, power__kw_ VARCHAR)
### Question:
What's the call sign that has 20kw of power?
### Answer:
SELECT call_sign FROM table_name_17 WHERE power__kw_ = "20kw"