What are the imperial size for the unit that has a ratio of 1/20?
CREATE TABLE "liquid_measures" (
  "unit" text,
  "russian" text,
  "translation" text,
  "ratio" text,
  "cubic_inches_exact" text,
  "metric_value" text,
  "imperial" text,
  "us_customary" text
);
SELECT "imperial" FROM "liquid_measures" WHERE "ratio"='1/20';