. _______ for your help, we'd never have been able to get over the difficulties.
A、Had it not
B、If it were not
C、Had it not been
D、It we had not been
【正确答案】：C
【题目解析】：C【句意】如果没有你的帮助，我们不会克服那些困难。【解析】根据句子结构，我们可以看出逗号后面是使用了虚拟语气的主句，因此，须填入表示与过去情况相反的虚拟条件句，“if it were not for …”这一结构表示同现在事实相反的假设，意为“如果不是……”，例如：If it weren't for his wife's money, he'd never be a director.”如果不是他妻子有钱，他永远不会成为一名董事。If it were not for his help, I would never study here．如果没有他的帮助，我永远不会在这儿学习。因此，BIf it were not 错误。“if it had not been for …”的倒装形式为“had it not been for …”，表示与过去事实相反的假设，意为“如果当时没有……”，主句谓语形式是“would ＋ have done”，例如：If it had not been for Dr. Li, he would have died of smallpox. 如果当初不是李医生的话，他已死于天花了。Had it not been for his carelessness, the project wouldn't have failed. 当时如果不是他粗心的话，这项工程不会失败。因此，C. Had it not been正确，A. Had it not错误（如果后跟been，就是正确的了），D. If we had not been无此结构。
