adjacency pair
【正确答案】：If the current speaker selects the next speaker, he or she usually also selects the type of next utterance by producing the first part of an adjacency pair, for example, a question which constrains the selected speaker to produce an appropriate answer. An adjacency pair is a two-turn sequence of adjacent utterances by successive speakers, in which the first utterance sets up an expectation for the second, such as question-answer and greeting-greeting.
