Introductionsn.说明；介绍名词introduction的复数形式.introductionn.介绍；引进；序言；导论introduction pneumatic valve进气阀Introduction to Economic Law经济法概论introduction to the training培训介绍Introduction to Criminal Law刑法概论Introduction and performance引种表现Introduction to Data Systems数据系统导论introduction and cultivation引种栽培introduction of contaminants机械杂质污染introduction and maintenance引种与养护introduction into daily life生活化