CREATE TABLE "long_vowels" (
  "long_vowels" text,
  "17th_c" text,
  "american" text,
  "british" text,
  "australian" text
);

Question: What's the American pronunciation when the Australian is əʉ?
SQL: SELECT "american" FROM "long_vowels" WHERE "australian"='əʉ';

Question: What is the 17th c. pronunciation when the british is əʊ?
SQL: SELECT "17th_c" FROM "long_vowels" WHERE "british"='əʊ';

Question: What is the 17th c. pronunciation when the British is i and the long vowels are e /iː/?
SQL: SELECT "17th_c" FROM "long_vowels" WHERE "british"='i' AND "long_vowels"='e /iː/';

Question: What's the British pronunciation when the American and Australian is i?
SQL: SELECT "british" FROM "long_vowels" WHERE "american"='i' AND "australian"='i';