本來叫----If it should rain ,the crops would be saved.要是下雨,莊稼們就有救了．
If it should rain 是對將來進行虛擬的表達
這里,倒裝了－－－－去掉IF,把助動詞SHOULD提前,意思不變
虛擬條件句的從句部分如果含有were,should,或had,可將if省略,再把were,should或had 移到從句句首,實行倒裝.
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：
在虛擬語氣的從句中,動詞'be'的過去時態(tài)一律用"were",不用was,即在從句中be用were代替.
If I were you,I would go to look for him.
如果我是你,就會去找他.
If he were here,everything would be all right.
如果他在這兒,一切都會好的.