Walter offered us a lift when he was leaving the office but our work we refused the offe

问题补充：

Walter offered us a lift when he was leaving the office, but our work ,we refused the offer.

A. not finishing

B. had not been finished

C. not having finished

D. not having been finished

答案：

A. not finishing

B. had not been finished

C. not having finished

(答案→)D. not having been finished

解析：考查独立主格结构。首先排除B项；工作应当是被做，排除A、C两项；故选D项。