答案:while the meaning of a sentence is abstract, and decontextualized, that of an utterance is concrete, and context- dependent. The meaning of an utterance is based on sentence meaning ; it is the realization of the abstract meaning of a sentence in a real situation of communication, or simply in a context. ;some utterances do not, and some cannot even be restored to complete sentences. For example, "Good morning!"Hi!” and “ Ouch! ” are all utterances,