text: 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_20 (service VARCHAR, unit VARCHAR, rank VARCHAR)
  ### Question:
  Name the service for 7th marines rank of sergeant
  ### Answer:
  SELECT service FROM table_name_20 WHERE unit = "7th marines" AND rank = "sergeant"