—It was cold and the road was icy.
—It a fortable journey.
A. can’t be
B. shouldn’t be
C. mustn’t have been
D. couldn’t have been
网友回答
A. can’t be
B. shouldn’t be
C. mustn’t have been
(答案→)D. couldn’t have been
解析：考查虚拟语气.句意:天很冷,道路很滑.——那不会是一个舒适的旅程。由上文的的时态可知下文表示是对过去的推测，故选D。