分析her choice was whom to ask to sleep over after the operati

主语：her choice 她的选择系动词：was 是表语：whom to ask to sleep over after the operation, 要问谁在手术后沉睡不醒（ask sb. to sleep over） 【不定式动词】ask 【不定式宾语】whom 【不定式宾补】to sleep over after the operation非限制性定语从句：which meant a bad night on couch那意味着是一个睡在躺椅上的不舒服的夜晚 注释：“wh- 疑问词+ 不定式”具有名词性,常用作宾语、表语或主语.此处是表语,也可以改写为表语从句whom she could ask to sleep over.非限制性定语从句的which 指代上文提到过的sleep over after the operation,意思是“那种事情/那种情况”.另如：He left early, which was wise. 他早早地离开,那是很明智的.