问题
选择题
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
答案：D
考查虚拟语气。But for“要不是......”，相当于if虚拟条件句，与过去事实相反，主句用would/should/could have done。句意“要不是他们的帮助，我们不可能及时完成计划。”故选D。