-----I called you at about half past eight last night but nobody answered.
-----Oh, I in my office at that time.
A. will work
B. had worked
C. worked
D. was working
网友回答
A. will work
B. had worked
C. worked
(答案→)D. was working
解析：考查时态。句意：昨天晚上大约八点半卧给你打电话了但是没人接。噢，在那时我正在办公室工作。在过去某一时刻正在进行的动作应用过去进行时态。所以选D。