jimmy goes to see his aunt --------------every week.填for 还是at 还是不填?

jimmy goes to see his aunt --------------every week.填for 还是at 还是不填?
jimmy goes to see his aunt --------------every week.填for 还是at 还是不填?

jimmy goes to see his aunt --------------every week.填for 还是at 还是不填?
不填
every week就副词做状语