状语从句中
在时间、条件、原因、方式等状语从句中，主、从句的动作如果先后发生，动作在前的，要用过去完成时，动作在后的要用一般过去时。如：
The land came in sight after we had sailed for ten days. （我们在海上航行了十天，终于看见了陆地。）
If she had said that, she told a real whopper. （要是她那么说的，她就是说了个大瞎话。）
I remained up because my uncle had come to see me. （因为我叔叔来看我，所以我一直没有睡。）
Everything fell out as we had anticipated. （一切结果正如我们所预料的那样。）
