The discipline that studies the rules governing the formation of words into permissible sentences in languages is called s（）

Morphology studies how words can be formed to produce meaningful sentences.

Semantics

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.

General linguistics is generally the study of language as a whole.

Language is p（）in that it makes possible the construction and interpretation of new signals by its users. In other words, they can produce and understand an infinitely large number of sentences which they have never heard before.

The study of meaning in language is known as semantics.

Syntax is different from morphology in that the former not only studies the morphemes, but also the combination of morphemes into words and words into sentences.

Language is a system of a（）vocal symbols used for human communication.

Findings in linguistic studies can often be applied to the settlement of some practical problems. The study of such applications is generally known as a（）linguistics.