状语从句It was a long time before I went to sleep again.过了很长时间我才
状语从句It was a long time before I went to sleep again.过了很长时间我才睡着 为什么不是it had been It was a long time before I went to sleep again. 过了很长时间我才睡着 为什么不是it had been a long time 不应该用过去完成时吗?. 这句话是句比较经典的状语从句.是不会有错的.