—Why didn’t you turn up last night Huck? —I to go for a walk but someone called and I c

问题补充：

—Why didn’t you turn up last night, Huck?

—I to go for a walk, but someone called and I couldn’t get away.

A. was planning

B. planned

C. had planned

D. would plan

答案：

A. was planning

B. planned

(答案→)C. had planned

D. would plan

解析：考查虚拟语气：句意：--昨晚你怎么不出现？--我正计划去散步呢，有人叫我，我走不开。Had planned是一种虚拟语气“本打算做却没做”，选C。