contexts语境contextn.上下文；环境；背景context-embeddedness情景嵌入context transformation内容转变context classification背景知识分类context sensitive help上下文相关帮助context-relationship上下文依赖关系context-free grammar上下文无关文法context-free program上下文无关程序context sensitive rule语境制约规则context of translation翻译语境Context-aware system上下文感知系统