信息描述是信息组织与存储中最重要的环节之一，信息描述的基本对象就是信息的外部特征和信息的内容特征。

单项选择题信息检索语言主要分为分类检索语言和主题检索语言。

多项选择题When composing the concluding paragraph you should ______. A、begin by stating a new point of view B、expand information from specific to general C、remind the reader what you have mainly talked about D、stress the importance of the whole essay E、use the tone different from the introduction