做反义疑问句的时候 首先要搞清楚助动词是哪一个
例如You must have been playing tennis at the time,这句话中have做助动词 引导现在完成进行时 故应该是
You must have been playing tennis at the time ,haven't you
She must have a kind mother,这句话中must表示推测,而不是表“必须”,反意疑问句应该提取后面的助动词 have做的是实意动词 表示“有”的意思 其助动词应该是do
因为是第三人称单数 所以应该是She must have a kind mother,doesn't she?