【正确答案】正确答案：Duality refers to the fact that in all languages so far investigated there are two levels of structure or patterning. At the first, higher level, language is analyzed in terms of combinations of meaningful units (such as morphemes, words etc.) ; at the second, lower level, it is seen as a sequence of segments which lack any meaning in themselves, but which combine to form units of meaning. For example, a syllable is the smallest unit that is normally spoken by itself, and scores of syllables become the carriers of hundreds of meaningful segments of words that are called morphemes.