高考英语必背句型：before…特殊用法

　　…before…特殊用法(2)“过了多久才……”或“动作进行到什么程度才……”
　　[例句]
　　They walked about fifty miles to the west before they saw a village.
　　他们西行50英里才看到一个村庄。
　　The workers worked day and night about three days before everything returned to normal.
　　工人们连续工作3天才使一切恢复正常。
　　He almost knocked me down before he knew it.
　　他几乎撞到我了才意识到。
　　We had walked a long way before we found some water.
　　我们走了很长的路才找到一点水。
　　Five years went by before I knew it. 不知不觉，五年过去了。