All the preparations for the task and we're ready to start.A. completedB. have complete

问题补充：

All the preparations for the task ， and we e ready to start.

A. completed

B. have completed

C. will be completed

D. have been completed

答案：

A. completed

B. have completed

C. will be completed

(答案→)D. have been completed

解析：D 考察动词时态。句意：这项任务的所有准备工作都已经完成，我们准备开始了。意为准备工作是否完成影响到我们现在是否能够开始，所以此处表示过去已经发生的动作对现在产生的影响，使用现在完成时。而准备工作和完成构成被动关系，所以使用完成时的被动语态。故D正确。