Mary couldn't have received your letter;otherwise she___ to your birthday party.A.will comeB.would comeC.would have comeD.had come答案是C、why?

can’t / couldn’t have couldn't have done和couldn't do的区别 try as she might ,Mary couldn't get the box Mary couldn't have received your letter;otherwise she___ to your birthday party.A.will comeB.would comeC.would have comeD.had come答案是C、why? I couldn’t have said it better. they couldn't have done better是什么意思 i couldn't have enjoyed any more Mary ______ my letter; otherwise she would have replied before now.A.has receivedB.ought to have receivedC.couldn’t have receivedD.shouldn’t have received为什么不是D how mary regretted( )her boyfriend so rudely though she couldn't bear him smoking in her office.a.being treatedb.to treat c.to have treatedd.having treated 完成时态的用法mary couldn't have received my letter,or she have replied the letter last week.有了具体的last week 为什么还要用完成时态?为什么用couldn't 能直接用 mary haven't received my letter 还有一个句子请帮忙 couldn't don't have to needn't的区别 should have done ,shouldn't have done.could have done,couldn't have done Mary couldn't run very fast because she had a sore back.同义句 Yesterday Mary couldn't finish her homework,so she has to go on 什么 it this Mary COULDN'T make herself ____attention toBECAUSE HER CLASSMATES MADE SO MUCH NOISE.答案为paid , Mary ( )( ) her key to the bicycle yesterday.为什么是couldn't find,而不是found? couldn't have done,不可能已经?请举例说明用法? We couldn't have played worse翻译啊