Should it rain,the crops _____.

本来叫----If it should rain ,the crops would be saved.要是下雨,庄稼们就有救了．
If it should rain 是对将来进行虚拟的表达
这里,倒装了－－－－去掉IF,把助动词SHOULD提前,意思不变
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.
注意：
在虚拟语气的从句中,动词'be'的过去时态一律用"were",不用was,即在从句中be用were代替.
If I were you,I would go to look for him.
如果我是你,就会去找他.
If he were here,everything would be all right.
如果他在这儿,一切都会好的.