I had wanted to help you last night but I couldn't spare any time, for I＿＿＿a position which I have to hand in this morning.
A. wrote
B. was writing
C. had written
D. have written
网友回答
A. wrote
(答案→)B. was writing
C. had written
D. have written
解析：考查时态：句意：昨天晚上我本来想帮助你的，但是我腾不出时间，因为我正在写一篇今天早上要交的作文。因为是昨天晚上正在做…，用过去进行时，选B。