19.10 表示"一…就…"的结构
 
 hardly/scarcely…when/before, no sooner…than 和as soon as都可以表示"一…就…"的意思,例:

 I had hardly / scarcely got home when it began to rain.
 I had no sooner got home than it began to rain.
 As soon as I got home, it began to rain.

 注意:如果hardly, scarcely 或no sooner置于句首,句子必须用倒装结构:
 Hardly / Scarcely had I got home when it began to rain.
 No sooner had I got home than it began to rain.