主系表结构后面的 to do 形式是什么成分?比如?I 'm sorry to hear that 里的to hear

主系表结构后面的 to do 形式是什么成分?比如?I 'm sorry to hear that 里的to hear I'm sorry to hear that. 这个句子的to hear在句子中做什么成分? I'm sorry to hear that语法分析to hear that做什么成分 I'm sorry to hear that语法分析to hear that做什么成分啊 I‘m sorry to hear that中to hear不定式做什么成分? i'm sorry (to hear)that为什么填to hear I'm sorry to hear that.的意思! I'm sorry to hear that.的中文意思 i‘m sorry to hear that的回答 I'm sorry to hear that .作文 I‘m sorry to hear that. 翻译.I'm sorry to hear that.