D（）is one of the design features of human language which refers to the phenomenon that language consists of two levels: a lower level of meaningless individual sounds and a higher level of meaningful units.

Langue refers to the a（）linguistic system shared by all the members of a speech community while the parole is the concrete use of the conventions and application of the rules.

Chomsky defines “competence” as the ideal user’s k（）of the rules of his language.

The distinction between competence and performance was proposed by F. de Saussure.

Modern linguistics regards the written language as primary, not the written language.

A diachronic study of language is the description of language at some point in time.

Modern linguistics is different from traditional grammar.

Modern linguistics is mostly prescriptive, but sometimes descriptive.

Sociolinguistics is the study of language in relation to society.

Social changes can often bring about language changes.