"the source of obligation"是什么意思

"the source of obligation"是什么意思 英语翻译source of the trial and error is the source of our knowledge是什么意思? the lack of responsibility and obligation It is the source of Mouth is the source of 英语翻译Definition of the information/data Obligation of the Ser 语法分析 accept the obligation of revealing the course of reason money is the source of the happy Describe the source of the family. passion is the source of our happiness The source of Dickinson's death poems?