All the task ahead of time so they decided to go on holiday for a week.A. having finishe

问题补充：

All the task ahead of time, so they decided to go on holiday for a week.

A. having finished

B. had finished

C. having been finished

D. had been finished

答案：

A. having finished

B. had finished

C. having been finished

(答案→)D. had been finished

解析：这题考查句式，so引导的是结果状语从句，所以前面是主句，应该填谓语动词，时间是发生在they decided to go on holiday for a week.之前，而且task和finish是被动关系，用过去完成时的被动式，选D。