问题补充:
We have hurried all the way to the airport - the flight was called off because of the foggy weather.
A. mustn’t
B. couldn
C. needn’t
D. wouldn’t
答案:
A. mustn’t
B. couldn
(答案→)C. needn’t
D. wouldn’t
解析:考查情态动词的完成式:句意:你不必一路赶到机场,因为大雾天气航班已经推迟了。Must和完成式连用,用于肯定句,couldn’t have done过去不可能做了,needn’t have done过去本没有必要做…而做了,wouldn’t have done过去本不会做而做了。选C。