几个英语问题..关于情态动词的

几个英语问题..关于情态动词的
1.will,would,shall作为情态动词时的用法
2.can have done 的意思
3.can be 能表示推测吗
4.would like to,should like
5.By no means________misunderstand you
A.could we B.shall we
C.we shall D.we can
为什么B不可以?
6.I knew that if I wasn't able to avoid a mistake,chances were that no other doctor________.
A.should have been B.could have been
C.ought to have been D.must have been
为什么?顺便解释下句子的意思.
第6题少了个either
6.I knew that if I wasn't able to avoid a mistake,chances were that no other doctor________,either

1.will,would,shall作为情态动词时的用法
will:1.构成一般将来时e.g:I will go to bed.
2.表达委婉的询问语气e.g:Will you please close the door?
would:1.表委婉语气（可与will互换）：e.g:Would you please close the door?
2.表愿望或请求：I would like to do that.
shall:1.构成一般将来时,用于第一人称e.g：I shall go to the bed.
2.Shall用于第二、第三人称,表示说话人给对方命令、警告、允诺或威胁.e.g:You shall fail if you don't work harder.（警告）
He shall have the book when I finish reading.（允诺）
He shall be punished.（威胁）
3.建议：e.g:Shall we go to the park.
2.can have done 的意思
本可以.表示一已经做完的事,含有一种抱怨的意义
e.g:You can have eaten it.
3.can be 能表示推测吗
不可以.表推测时,英语中只使用must,may,might,may not和can't.这五个表达的语气依次递减：
must:一定（语气肯定）
may：也许（不很肯定）
might：或许（比may语气更弱）
may not：也许不（表否定）
can't：一定不（must的反义）
推测现在的事情用must,may,might,may not和can't+do或be
e.g.She must be at home now.
The boy may play now.
推测过去的事情用must,may,might,may not和can't+have done
e.g.She might have been ill yesterday.
He must have hold the party.
注意：表推测的must,may,might,may not和can't是不可以与I think...连用.因为I think...已有推测的含义,故不能连用
4.would like to,should like
would like to指想要做某事.同义词是want和feel like doing
至于should like to根本没有这种用法
5.By no means________misunderstand you
A.could we B.shall we
C.we shall D.we can
答案是A 为什么B不可以?
shall we表示的是疑问语气.这里是将状语提前,所以要倒装,将情态动词提前.实际上可以说成We could misunderstand you by no means.
6.I knew that if I wasn't able to avoid a mistake,chances were that no other doctor________,either.
A.should have been B.could have been
C.ought to have been D.must have been
答案是B 为什么?顺便解释下句子的意思.
这里could have been是在虚拟语气中使用的.有机会
意思是我知道假如我不能承受一个错误,其他医生都没有机会的.