问题补充:
Walter offered us a lift when he was leaving the office, but our work , we refused his offer.
A. not finishing
B. had not been finished
C. not having finished
D. not finished
答案:
A. not finishing
B. had not been finished
C. not having finished
(答案→)D. not finished
解析:在这里,our work处在逗号位置,作整个句子的原因状语,这里应填非谓语动词。work和finish存在逻辑上的被动关系,所以应该用过去分词,故选D。