it在这两句中代替的是什么?这两句中weren't和hadn't been分别虚拟的有什么不同?

You wouldn't anywhere if it weren't for Ruth.句中的it 指形势,情况.含 weren't的if从句是对将来的虚拟If it hadn't been for Margaret,I might not have understood句中的it 指心目中的事,情况.含hadn't been的if...含 weren't的if从句是对将来的虚拟不是很清楚，能给我设一个情景吗You wouldn't anywhere if it weren't for Ruth意思是：要不是有露丝(的帮助），你将不会有任何成就。又如， 假定现在天气非常干旱，要是今后一周内不下雨，庄稼就会死掉，没发救了。If there weren't any rain , the crops would die.in a week.含if从句的虚拟语气表示对将来的虚拟时，If 从句中有三种谓语动词的形式1，动词的过去式，2，should +动词原形 3.were to do所以上面句子可改为：If it didn't rain , the crops would die in a weekif it shouldn't rain , the crops would die in a week if it weren't to rain ,the crops would die.in a week