虚拟条件句的倒装

　　虚拟条件句的从句部分如果含有were、should、或had可将if省略，再把were、should或had移到从句句首，实行倒装。

　　Were they here now, they could help us.

　　=If they were here now, they could help us.

　　Had you come earlier, you would have met him

　　=If you had come earlier, you would have met him.

　　Should it rain, the crops would be saved.

　　=Were it to rain, the crops would be saved.