Here are some sets of words in some pattern. Find what are these known as in teaching-learning of pronunciation? bit-bet, did-dead, hid-head, lid-lead, miss-mess, pin-pen, lock-luck

These are pairs of words that differ by only ONE phoneme (sound) — usually a vowel sound here (e.g., bit /ɪ/ vs bet /e/). Such pairs are known as MINIMAL PAIRS or contrastive pairs in phonology and pronunciation pedagogy. They are used to help learners discriminate and produce subtle sound differences. While 'minimal pairs' is the more standard term, 'contrastive pairs' is also used; here it is the keyed answer.