【问】 1987年高考英语试题第三大题第6小题：

There was plenty of time. She________.

A. mustn't have hurried B. couldn't have hurried

C. must not hurry D. needn't have hurried

规定的答案为D。但我认为选B也是对的。您的意见如何?

【答】 同意你的意见。就上面孤立的句子而言，选B同样也是正确的。couldn't have done常常用来表示从现在或过去看来过去不可能发生某事。上道题中的She couldn't have hurried.意为：“她不可能很慌忙的”。请对比下列例句：

1. “You realize that you were driving at 100 mph，don't you?”

“No，officer，I ____，This car can't do more than 80.”

A. needn't have been B. may not have been

C. didn't need to be D. couldn't have been

2. ...her father could not have made such a mistake. (New Concept English，Book 3，L.60)

…她父亲不可能犯这样的错误。

3. They couldn't have left so soon. (Mis)

他们不可能那么早就走了。

请做下面的英语试题：

1. Mary____my letter，otherwise she would have replied before now.

A. has received B. ought to have received

C. couldn't have received D. shouldn't have received. (攻读硕士学位研究生入学考试英语试题，1991)

2. ——There were already five people in the car but they managed to take me as well.——It____a comfortable journey.

A. can't be B. shouldn't be

C. mustn't have been D. couldn't have been(全国高考英语试题，1995)