— How did the accident happen?
— You know, it difficult to see the road clearly because it .
A. is…was raining
B. was…had rained
C. is…is raining
D. was…was raining
网友回答
A. is…was raining
B. was…had rained
C. is…is raining
(答案→)D. was…was raining
解析：英语句子注意时态上的一致性，根据句意：因为天气正在下雨，看清楚路是很困难的。后一空用过去进行时表示动作过去正在进行，同样时态保持一致，前一空用一般过去时，故选D.