What is the pair of words that is repeated the most times? Identify them by their ID.
repeated the most times refer to MAX(occurrences); pair is a relationship of two words: w1st and w2nd, where w1st is word id of the first word and w2nd is a word id of the second word;
SELECT w1st, w2nd FROM biwords WHERE occurrences = ( SELECT MAX(occurrences) FROM biwords )