请问it be…before…的句型用法…比如说it was 3 years before he …

请问it be…before…的句型用法…比如说it was 3 years before he … it will be…before和 it was …before的区别 It was...before 句型 It was three years before he came It was /will be …before啥意思? it won't be very long before .句型用法 it will be +段时间+before .句 英语翻译还有It will be three years before he graduated. 请问before的用法句型! It's ...before...的句型 It was…before…后面用什么时态呢? it would be months before he was()for work. It was 3 days before he went to Beijing.It will be not long