【答案解析】Langue refers to the abstract linguistic system shared by all the members of a speech community. Langue is the set of conventions and rules which language users all have to abide by. It is abstract and relatively stable.

【答案解析】Parole refers to the realization of langue in actual use. It varies enormously according to individuals. The speeches, the idiosyncratic utterances made by individuals are all examples of parole.

【答案解析】Allophones are the different members of a phoneme, sounds which are phonetically different but do not make a word different from another in meaning. In other words, it is the different realization of the same phoneme in different phonetic environment. For example, the aspirated [p ^h ] and the unaspirated [p ⁼ ] are allophones of the phoneme/p/.

【答案解析】Semantic field is sometimes also called lexical field. It refers to an organizational principle that the lexicon and groups of words in the lexicon can be semantically related in such a way that they are from the same area of knowledge or interest; and there is a meaning inclusion relation between the items in the field and the field category itself. For example, the semantic field of agriculture includes: farm, farming, tractor, meadow, crop, and so on.

【答案解析】Cohesion refers to the grammatical and/or lexical relationships between the different elements of a discourse. This may be relationship between different sentences or between different parts of a sentence. It can be achieved by cohesive devices include reference, substitution, ellipsis, conjunction and lexical cohesion.