单选题 1. Which of the following sentences is correct?

A、 Had not it been for their help, he could not have finished the task on time.
B、 It hadn't been for their help, he could not have finished the task on time.
C、 Had it not been for their help, he could not have finished the task on time.
D、 Hadn't been for their help, he could not have finished the task on time.

【正确答案】 C

【答案解析】 该题是语法结构题，考查虚拟语气用在If it (be) not for...句型中的意义和用法，同时考查虚拟语气条件句(带否定词)的倒装用法。
该句型的意思是“要不是……”，相当于but for和without，如：If it were not for the leadership of the Party, we could not be living a happy life today. 要不是有了党的领导，我们今天就不可能过上幸福生活。在该题中，虚拟语气用来表示与过去事实相反；从句中的if被省略，第一个助动词要提到主语前面构成倒装，但是不能把否定助动词not一起提前。因此，选项C为最佳答案。