But for their help we the program in time.A. can not finishB. will not finishC. had not fi

问题补充：

But for their help，we the program in time.

A. can not finish

B. will not finish

C. had not finished

D. could not have finished

答案：

A. can not finish

B. will not finish

C. had not finished

(答案→)D. could not have finished

解析：本题考察虚拟语气.But for起到了对过去虚拟的条件句作用,后面自然要选would/could/might/should+have done结构了.