虚拟条件句的倒装应该怎样？

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.

同虚拟句一样