英语中何时使用wouldn,t have done shouldn,t have done couldn,t have done needn,t have donewouldn have done shouldn have done could have done needn have done 呢

英语中何时使用wouldn,t have done shouldn,t have done couldn,t have done needn,t have donewouldn have done shouldn have done could have done needn have done 呢 请问英语中couldn't wouldn't needn't mustn't的区别与用法? 英语：现在完成时应该什么时候使用?还有I have been doing这种形式又应该何时使用? He should have known the police wouldn't allow it but he didn't.He should have known the police wouldn't allow it_______.A.and he did B.but he didn't C.but he couldn't D.but he had新概念英语第二册中65课的题,为什么选择B项呢?如何 在英语中,表示年龄时,连字符如何使用,谓语动词何时单何时复 英语虚拟语气的一道题if i had known that,i____so.A.wouldn't doB.wouldn't have done选哪个,请说明理由. Without your help,I wouldn't have achieved so much.为什么句中要用wouldn't have achieved? 新概念英语中多次出现I have bought a house.现在完成时,不是不能使用非延续性动词吗,若能用,何时用? our monitor was absent,otherwise I wouldn't have taken the chair这句英语怎么翻译? 高一英语题（关于虚拟语气）Having been informed about the meeting,I ( ) it.A.don't missB.wouldn't missC.hadn't missedD.wouldn't have missed为什么选D? i wouldn't have missed it for anything.译 But that you helped me,I wouldn’t have succeeded. I Wouldn't Have Missed It For The World 歌词 I wouldn't have wanted to miss single I probably wouldn't have to say spank as much. i wouldn't have bet you'd make it this I wouldn't have her do that.翻译下 i wouldn't have been +过去分词是什么时态?例句 i wouldn't have been scared anyways