must的反义疑问句问题.
问题描述：
must的反义疑问句问题.
请重点说一下must have done把.我不太明白,为什么有些用don't,有些用haven't,有些是be动词呢?
she must have finished reading the novel last night,____?
答
she must have finished reading the novel last night,【didn't she 句中有时间的标志性短语 last night,时态就只能用一般过去时,不可以用完成时.【反义疑问句肯定要根据时态,所以是didn't she 】陈述部分有must 的...