中考英语知识点：知识扩展

　　1. It is since从…以来多长时间了(因为since +从句或名词，表示一段时间)

　　It is five years since we met last time.从我们上次见面已经五年了。

　　2. It is +before…(…才)

　　It was a long time before I went to sleep again.

　　过了很长时间我才睡着。

　　It was an hour before(=until) the police arrived.

　　过了一个小时，警察才来。

　　3. 由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句。这些连词都表示"一…就"。例如:

　　I will go there directly I have finished my breakfast. 吃完早饭，我立即到那里去。

　　The moment I heard the news, I hastened to the spot.我一听到消息，马上赶到了出事地点。

　　As soon as I reach Canada, I will ring you up. 我一到加拿大，就给你来电话。

　　4.【注意】hardly(scarcely, rarely)…when / before, no sooner…than相当于as soon as之意。