一、情态动词： 53
She （D） fifty or so when I first met her at a conference
(2009) A
had been B
must be C
has been D
must have been Key: 情态动词 must 表示很有把握的推断
对于现在事情的肯定推断用 must do ,而对过去的推断，要用 must have done
本句是对她过去年龄的肯定推测
Aren’t you tired
I（A）you had done enough for today
（2009） A
should have done B
must have done C
might have done D
could have done Key: should have done 意思是本来应该做某事，而实际没做，符合此处语义逻辑关系
Must have done 表示对过去事情的猜测，might 与 may 意思相同，但可能性更小
多用于虚拟语气结构中
Could have done 是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做
Nancy's gone to work but her car's still there
She（A） by bus
(2010) A
must have gone B
should have gone C
ought to have gone D
could have gone Key: must 用于肯定句中比较有把握的推测，意为“一定”
当 must 后接完成时，表示已发生的事情的推测
根据句意，此处应该为有把握的推测
二、非谓语动词 51
What a nice day
How about the
