If it had not been for your help yesterday, I couldn't have caught the train.

如果昨天没有你的帮助，我就赶不上火车。（事实是你昨天帮助我了）

There he had to remain for four long, weary months. And if it had not been for a very lucky chance, he probably would have had to stay there longer.

他在那里呆了足足有四个月，疲惫的四个月。如果不是有了一个极其幸运的机会，他本来还要在那继续呆下去。

This arrangement would have worked well enough if it had not been for the disputes between Snowball and Napoleon.

本来，要是斯诺鲍和拿破仑相互之间不闹别扭，整个程序会进行得很顺利。