What Frequency has the Identifier of CBFX-FM-6?
CREATE TABLE "s_rebroadcaster_of_cbfx_fm" (
  "city_of_license" text,
  "identifier" text,
  "frequency" text,
  "power" text,
  "class" text,
  "rec_net" text
);
SELECT "frequency" FROM "s_rebroadcaster_of_cbfx_fm" WHERE "identifier"='cbfx-fm-6';