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

Linguistics

Phonetics

In the study of linguistics, hypotheses formed should be based on language facts and checked against the observed facts.

Semantics

Modern linguistics is different from traditional grammar.

The study of the ways in which morphemes can be combined to form words is called morphology.

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.

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

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