单选题 Walter offered us a lift when he was leaving the office, but our work ______, we declined the offer.
A. not being finished B. had not been finished
C. not having been finished D. was not finished

【正确答案】 C

【答案解析】[解析] 句法概念题。本句大意是：Walter。离开办公室时提出让我们搭他的便车，因为我们的工作还没做完，就谢绝了。but后因没有从属连词引导，所以不能用从句，应用独立主格结构表示原因，用分词的否定完成时形式表示还没有做完。