If it were not for ……
结构︰if it were not for+名词/子句，主词+would/should 等+原形动词…
说明︰此句型意为“若非（有）…”。此类句构专门用于表示与现在事实相反的<假设语气>.亦可用“but for+<名词>”或“without+<名词>”代替。were 可以提前，省略 if，如例句3.
If it were not for his presence, I would punish you.
要不是他在场，我会处罚你的。
But for your advice, I should have failed.
要不是你的忠告，我会失败的。
But for music （=Were it not for music）, life would be dull.
要不是音乐，人生会很无聊。
If it were not for oxygen and nitrogen in the air, no man could live on the earth.
大气中如果没有氧和氮，人就无法生存于地球了。
Without air, all living things would die.
若非空气，所有的生物都会死亡。
Without newspaper, we would get behind the times.
要不是报纸，我们都赶不上时代了。
I should be lonely, were it not for the birds and the flowers.
我会寂寞，若非有鸟也有花。
Were it not for his help, I could not finish the work.
若非有他的帮助，我就不能完成这件工作。
Were it not for science, we could not live a comfortable live.
若非科学，我们无法过着舒适的生活。
