Use of subheadings in subject indexing of medical literature;

Controllable verbs and uncontrollable verbs, a new classification of Chinese verb, occupy an important position in the research of the modem Chinese verbs.

When teaching vocabulary both teachers and students ought to know which words are passive words, and which are active ones.

Its main idea is to divide a document into two parts:one is only composed of subject words(named as subject block),and the other contains no subject words(named as non-subject block).

This paper introduces the basic concepts of the set theory, expounds the set analysis and operation of classification and subject words, and discusses the relations among the sets of the classification, non-controlled subject words and subject words.

Aim:to explore how to select suitable searching words(subject word and random word)in medical document retrieval.

Through comparing the functions of subject words and Keywords,this paper analyzes the application of two modes in network literature information index search,and probes into the developing trend of index language in network environment.

By using the special knowledge of Chinese Opera Science and the Library Classification Science,and connecting with the practical experience of the classification of the books,this paper probes into the set-up of the opera category and the set-up of the subjects in corresponding subject words indexes,and puts forward some suggestions.