_______ your valuable help, we couldn't have finished the experiment ahead of time.

2023-08-04

A.If it were not for
B.Had it not been for
C.Were it not for
D.If it has not been for

参考答案:B

考查虚拟语气。根据语境可知是与过去事实相反,如果省if,句子要倒装,倒装时要将助动词提前,故选B。

相关推荐