只有must be，没有must been，但有must have been。must是情态动词，情态动词之后只能是动词原形。must be表示对现在情况的肯定性推测，must have been是表示对过去情况的肯定性推测。
解析 没有,I mustn't 是不准的意思,加个have been a doctor是已经当上医生的意思,那就不成句子了,要说就说i mustn't be a doctor,但不能说I mustn't have been a doctor.结果一 题目 有没有这个说法:I mustn't have been a doctor.可以说mustn't```吗? 答案 没有,I mustn't 是不准的意思,...
you mustn't do it，语气比you must not do it 要重些，前者突出命令性，后者略显建议性 mustn't have been 一定没有……（强调主观推测/认为没有……）must haven`t been……（虽然也是主观推测/认为没有……，但强调客观上没有……的可能性）希望说明白了 ...
3 The room is in a terrible mess; it ___ cleaned.A. can’t have been B.couldn’t be C.mustn’t be D.mustn’t have been 4 The room is in a terrible mess; it ___ cleaned. A. can’t have been B. couldn’t be C. mustn’t be D. mustn’t have been 反馈 收藏 ...
They mustn't have been in the library because I saw them on the playground. ___ . 相关知识点: 试题来源: 解析 mustn't改为couldn't/can't 答案:mustn't改为couldn't/can't.考查句子改错.对过去发生的事情的否定推测用can't或couldn't,不可用mustn't. 他们不可能在图书馆因为我看见他们在...
答案解析 查看更多优质解析 解答一 举报 没有,I mustn't 是不准的意思,加个have been a doctor是已经当上医生的意思,那就不成句子了,要说就说i mustn't be a doctor,但不能说I mustn't have been a doctor. 解析看不懂?免费查看同类题视频解析查看解答 更多答案(5) ...
,是对过去发生事情的肯定推测;不存在mustn't have done的形式;can't have done表示不可能做了……,是对过去发生事情的否定推测。短语have been to表示去过(已经回来了),have gone to表示去了(还未回来)。根据句意可知,选C。常考的情态动词+have done结构还有,may/might have done:可能做了……,是对过...
百度试题 结果1 题目She mustn' t have been to your home.She doesn ' t know your address.相关知识点: 试题来源: 解析 答案: must n' t t can't 反馈 收藏
百度试题 结果1 题目 改错 She mustn't have been to your home. She doesn't know your address. 相关知识点: 试题来源: 解析mustn't→can't 反馈 收藏
ainadequacy 不适当[translate] avincent raris Vincent raris[translate] a令我不解的是 Make me relentless is[translate] aHe mustn't have been off long. I heard him make a call just now. 他不能是长的。 我听见他刚才打电话。[translate]